Download PDF Summer Bridge on Smart Agriculture June 15, 2022 Volume 52 Issue 2 People everywhere rely on agriculture in one form or another – for food, animal feed, fiber, and other necessities. The summer 2022 articles describe precision indoor farming and alternative protein food systems, advances in food processing, genome editing, digitalization, sustainable and regenerative agriculture, the role of a circular economy, and the important role of policy. Nanoscale Science and Engineering for Agriculture and Food Systems Tuesday, June 14, 2022 Author: Hongda Chen, Jason C. White, Antje J. Baeumner, and Dan Luo Nanotechnology will enable smarter strategies of food production while protecting the environment. National pursuit of nanoscale science and engineering (NSE) for agriculture and food systems started in 2002 with a strategic roadmap workshop organized by the US Department of Agriculture. The report of that workshop articulated a vision of scientific discovery and engineering innovation based on the understanding and control of matter at nanometer scale to solve pressing societal challenges facing agriculture and food systems (Scott and Chen 2003). To be effective, NSE in this area must involve at least the following: recognition of the tremendous potential for new scientific inquiries; multidisciplinary collaboration among the biological, physical, social, and regulatory sciences, engineering, and industry; significant advances in scientific exploration and engineering innovation, evidenced by numbers of publications, patents, and projects; and substantial investments by both the public (e.g., the National Nanotechnology Initiative) and private sectors. We highlight the most promising areas to ensure food security, support precision agriculture, improve food safety, and create value-added uses of nanobiomaterials. We then explain NSE’s importance for basic science and novel applications to support sustainability and address the most significant challenges facing agriculture and food systems. Sustainable Agricultural Production to Ensure Food Security Achieving and maintaining global food security is possible only with sustainable agricultural practices. Crop Production and Protection The Green Revolution of the 1950s and 1960s dramatically increased agricultural output through the development of higher-yield grains and the use of agrochemicals and irrigation, but it was not sustainable and the rate of annual crop yield increases has been declining since 1980 (Kah et al. 2019). This stands in stark contrast to the projected 70 percent increase in food production needed by 2050 to feed the world population of over 9 billion, further complicated by the changing climate. Agriculture is resource intensive and highly inefficient, consuming 6–30 percent of global energy production and 70–80 percent of fresh water (Wang et al. 2022). The efficiency of agrochemical delivery is also low: annual fertilizer losses from leaching, volatilization, or conversion to unavailable forms exceed 60–70 percent (Kah et al. 2019; Wang et al. 2022). For pesticides, less than 25 percent reaches the target, and 20–40 percent crop loss from pests and disease is typical (Kah et al. 2019).[1] FIGURE 1 Potential applications of nanotechnology in crop agriculture (Hofmann et al. 2020; reprinted with permission from Springer Nature Group). The goal is to dramatically increase yield per unit of input (inputs are soil, water, energy, agrochemicals, labor, and cost). Potential solutions are many (figure 1) but in all cases require a systems-level approach involving convergence of expertise in materials science, formulation chemistry, plant biology, agronomy, engineering, toxicology, agricultural economics, life cycle analysis, social science, and regulatory policy. A survey of 500 publications and 36,000+ patents on nanoscale pesticides showed that nanoscale strategies improve agrochemical delivery efficacy by 32 percent and reduce toxicity for nontarget receptors by 43 percent (Wang et al. 2022). Additional benefits include improvements in stress tolerance, yield, crop quality, and foliar attachment as well as decreased leaching potential. FIGURE 2 A Science Direct literature search shows a roughly 2000 percent increase in the number of submitted manuscripts in this area since 2001. The search used the following terms in the title, abstract, or keywords: AB = [((agri*) OR (agro*) OR (“crop protection”) OR (“plant protection”) OR (“crop yield”) OR (“plant yield”) OR (pesticide) OR (herbicide) OR (fertilizer) OR (micronutrient) OR (fungicide)) AND (nano*)]. Numerous nanoscale strategies have been explored over the past 2 decades (figure 2). Approaches include agrochemicals in nanoscale form (e.g., nutrient metal oxides) and nanoscale carriers to deliver cargo of interest where tunable chemistry at synthesis can “hardwire” nanoscale-specific biological benefits in the field. Certain nanoscale elements or element oxides promote tolerance to pathogen stress (CuO, S, SiO2, carbon nanomaterials [CNM]; Kang et al. 2021; Ma et al. 2020) and to abiotic stress such as salinity or drought (ZnO, CeO2, CNM) (An et al. 2020; Dimkpa et al. 2020; Pandey et al. 2018), or enhance electron capture/transfer to photosynthesis (Fe and Mn oxides; Wang et al. 2020a). Importantly, these benefits are observed only with nanoscale materials. Other techniques include the use of nanoscale biopolymers as responsive seed coatings (Xu et al. 2020), nanoscale materials to facilitate RNA interference for disease management (Shidore et al. 2021), and nano-enabled biofortification strategies to increase crops’ nutritional value (De La Torre-Roche et al. 2020). Livestock and Aquacultural Production Nanotechnology-enabled vaccines are sought to control infection in livestock to sustain a safe food supply and improve rural economic wellbeing (Chandrasekar et al. 2020). Biodegradable polymeric nanoparticles are another promising vehicle to deliver antibiotics and improve efficacy against enteropathogenesis in livestock (Paudel et al. 2019). NSE approaches also help minimize food waste and loss due to chemical and microbial deterioration, which are estimated to affect 30–60 percent of food production. For example, cellulose nanocrystals, corn protein (zein), and starch-based electrospun nanofibers can improve food safety and quality by releasing antimicrobial agents in response to bacterial enzymes or elevated humidity (Aytac et al. 2021). Nanotechnology-Enabled Sensors to Enhance Precision Agriculture and Food Safety Sensors used in precision agriculture and food safety are mostly based on physical or chemical principles for the detection of humidity, temperature, chloride ions, gases, and biological parameters such as estrous cycles or biogenic amines. New types of sensors are needed to address more complex questions involving challenging analytes, such as the metabolic state of a single plant, the local concentration of pesticides in a field, or the safety of foods beyond expiration dates. Nanotechnology can provide the technological boost for this new generation of sensors. In terms of existing technology, standard electrochemical biosensors are mounted on fish to monitor their cholesterol levels (Takase et al. 2014). But they perform for only 48 hours, require recalibration, and both vary with and degrade due to environmental conditions, making them ineligible for precision pisciculture. Nanostructured sensors that integrate additional functionality and that can easily be embedded in an animal, as is done with certain types of human health monitoring (Sharma et al. 2016), will solve this challenge and enable large-scale individual livestock monitoring. Similarly, the integration of sensors in plants will provide direct information on plant or crop health rather than monitoring soil composition to infer effects on plants. Research that started with measuring plant transpiration (Shihao et al. 2021) can now detect hormones, pesticides, and other biomolecules in cells, provide nondestructive sensing of plant metabolism and effects of chemicals, and inform precise agricultural practices (Ang et al. 2021; Yin et al. 2021). FIGURE 3 Food safety must be monitored ideally along the entire food value chain from farm to fork to identify possible degradation, contamination, and adulteration and enable the reduction of food waste and loss. To ensure food safety and prevent food waste and loss, monitoring throughout the food value chain is necessary—from agricultural production to food processing and manufacturing, distribution, retail, and the consumer (figure 3). Nanosensors for food packaging are a first step, with physical and gas sensing capabilities (Abad et al. 2007), and nanomaterials may also be applicable in packaging systems where high sensitivity is needed. Research shows that nanofibers can lower detection limits tenfold relative to bulk material for biogenic amines that indicate the safety of meat and fish products (Yurova et al. 2018). Nanosensors have the capability to enable sustainable agriculture by decreasing chemical and energy inputs while increasing output and product lifetimes. Connecting sensor outputs with data infrastructure and data analytical sciences can improve the decision making of agricultural and food enterprises. Nanobiomaterials for Value-Added Applications Most food packaging materials are from petrochemical manufacturers, and the nondegradable and nonrenewable nature of most synthetic polymers is of significant environmental concern, especially as more than 8 million metric tons of plastics are discarded annually into the oceans (Schmidt et al. 2017). This clearly is not sustainable. Novel Material Production from Biomass NSE research has provided many strategies to combat this challenge and to promote convergence with agriculture. A prime example is research involving DNA, which has been used as both a genetic and a generic material. DNA is nanoscale, renewable, degradable, and easily obtainable from biomass, including from agricultural production. The total amount of global biomass DNA is approximately 50 billion metric tons (Landenmark et al. 2015). FIGURE 4 A large-scale gel (left), a thin membrane (middle), and plastic toys (right) fabricated entirely from biomass DNA (Wang et al. 2020b; reprinted with permission from the American Chemical Society). DNA has been converted into bulk-scale membranes, fabrics, and plastics (Wang et al. 2020b; figure 4), hydrogels (Um et al. 2006; figure 5), and cell-free protein-producing gels for large-scale protein production (Park et al. 2009; figure 5). DNA can function as nanoscale barcodes (Li et al. 2005), as lifelike soft robots (Hamada et al. 2019; figure 5), or as an organizer for gold nanoparticles to obtain ordered superlattices with different plasmonic properties (e.g., different transmittal and reflectional colors) (Derrien et al. 2020; figure 5). FIGURE 5 Different applications of DNA as both a genetic and generic material. Top: Bulk-scale DNA hydrogels (Um et al. 2006; reprinted with permission from Nature Publishing Group). Middle left: DNA-gel-based synthetic cell producing green fluorescent proteins in a cell-free fashion. Middle right: Lifelike soft robot made entirely from DNA (Hamada et al. 2019; reprinted with permission from the American Association for the Advancement of Science). Bottom: Different plasmonic properties from gold nanoparticle assemblies organized by DNA materials (Derrien et al. 2020; reprinted with permission from Elsevier Ltd.). Nanobiomaterials Other nanobiomaterials include nanodiatoms from ocean and soil, and nanoparticles assembled from biology such as exosomes, nanofibers, and nanoscale celluloses. Some nanoscale cellulose products are abundantly available in agricultural crops and forest. Commercially manufactured cellulose nanocrystals and cellulose nanofibrils have been tested for applications such as food packaging, coatings, delivery of active payloads, industrial catalysts, and sensors (Li et al. 2021). For example, a promising technology using cellulose nanomaterial–based dispersion has been applied on delicate fruit buds of sweet cherry and apple trees for protection against frost damage (Alhamid et al. 2018). Bulk-scale, ultrastrong materials were fabricated using aligned nanocellulose fibers (Han et al. 2019). Nanocellulose membranes were also engineered into a device converting heat to electricity, demonstrating that nanocellulose is a promising sustainable material for harvesting energy (Li et al. 2019). Value-added realization of these products will increase economic revenue for farmers, strengthen a circular economy, and enable sustainable agriculture and food systems. NSE in Fundamental Agricultural Biology Research for Sustainability Improved Understanding from Molecular to Systems Levels Integration of nanomaterials in devices and systems has propelled the development of new tools for understanding and controlling agricultural biology at the molecular level. In situ gene editing improves plant production and product quality. Desirable transient expression is obtained using carbon nanotube–mediated DNA delivery without transgenic DNA integration in the host genome. Higher yields are possible as the nanocarrier protects cargo in transit from degradation, as demonstrated with arugula, wheat, and cotton (the latter two are particularly challenging to genetically transform; Zhang et al. 2021a). Furthermore, gold nanoparticles have revealed nanoparticle transport mechanisms in plants and enabled the efficient and safe delivery of molecules to plant cells, an example of “green nanoscience” (Zhang et al. 2021b).[2] Decoding and monitoring plant stress signaling to better understand plant diseases will enable timely deployment of effective and precise interventions. Nanobionics, involving specifically functionalized near-infrared fluorescent single-walled carbon nanotubes, is uniquely positioned to achieve this in a nondestructive way. These nanoprobes allow real-time in vivo spatiotemporal monitoring of endogenous H2O2 produced as a stress response (Lew et al. 2019). Nanotechnology-based Agricultural Products The generation and control of nanoscale materials afford engineers tremendous opportunities to use abundant agricultural biomaterials for novel applications to meet societal needs, as illustrated in the following: Biomanufacturing for cultured meat and seafood production, like tissue engineering in medicine, shows that nanoscale scaffolding supports cell alignment and muscle tissue formation that is scalable and safe. This supports a circular bioeconomy by using naturally abundant resources such as sugars from grains and cellulosic byproducts (Ostrovidov et al. 2014). Nanoparticles in combination with specific enzymes are a key component in cell-free synthetic biology that converts bulk feedstock molecules (e.g., sugar) into complex and highly nutritious food ingredients (vitamins, nutraceuticals, peptides, and proteins) (Díaz et al. 2021; Ellis et al. 2021). This conversion technology can be incorporated in distributed manufacturing plants built near feedstock sources in rural communities. Proteins responsible for photosynthesis may become the key component of sustainable solar cells rather than the current use of rare earth elements (Wolfe et al. 2021). Conclusion Looking at the short history of nanotechnology for agriculture and food over the past 20 years, numerous innovative concepts and prototypes of promising technologies have progressed toward societal benefit. Novel ideas and possibilities are constantly emerging as new properties, phenomena, and processes of nanoscale materials are discovered and created. Nanotechnology makes it possible to make agricultural systems more efficient, to directly probe biological systems, and to develop new, sustainable materials for diverse applications. NSE will enable agriculture and food systems to continue to support a planet that is more sustainable, safer, and healthier, even with high population and climate crisis conditions. Advances in NSE, along with other disciplines, will provide new fundamental knowledge about agricultural systems and enable smarter strategies of food production while protecting the environment. Scientists must continue to study environmental, health, and safety effects of these new systems to ensure responsible deployment. Convergence of multidisciplinary approaches has been critical to the successful exploration of NSE, and further efforts must include a broad range of disciplines, such as the social sciences, risk communication, and policy. Disclaimer The views expressed in this publication are those of the authors and not necessarily those of the US government. References Abad E, Zampolli S, Marco S, Scorzoni A, Mazzolai B, Juarros A, Gómez D, Elmi I, Cardinali GC, Gómez JM, and 5 others. 2007. Flexible tag microlab development: Gas sensors integration in RFID flexible tags for food logistic. Sensors and Actuators B: Chemical 127:2–7. Alhamid JO, Mo C, Zhang X, Wang P, Whiting MD, Zhang Q. 2018. Cellulose nanocrystals reduce cold damage to reproductive buds in fruit crops. Biosystems Engineering 172:124–33. An J, Hu P, Li F, Wu H, Shen Y, White JC, Tian X, Li Z, Giraldo JP. 2020. Molecular mechanisms of plant salinity stress tolerance improvement by seed priming with cerium oxide nanoparticles. Environmental Science: Nano 7:2214. Ang MCY, Dhar N, Khong DT, Salim Lew TT, Park M, Sarangapani S, Cui J, Dehadrai A, Singh GP, Chan-Park MP, and 2 others. 2021. Nanosensor detection of synthetic auxins in planta using corona phase molecular recognition. ACS Sensors 6(8):3032–46. Aytac Z, Xu J, Pillai SKR, Eitzer BD, Xu T, Vaze N, Ng KW, White JC, Chan-Park MB, Luo Y, Demokritou P. 2021. Enzyme- and relative humidity-responsive antimicrobial fibers for active food packaging. ACS Applied Materials & Interfaces 13(42):50298–308. Chandrasekar SS, Kingstad-Bakke B, Wu CW, Suresh M, Talaat AM. 2020. A novel mucosal adjuvant system for immunization against avian coronavirus causing infectious bronchitis. Journal of Virology 94(19):e01016–20. De La Torre-Roche R, Cantu J, Tamez C, Zuverza-Mena N, Hamdi H, Adisa IO, Elmer W, Gardea-Torresdey J, White JC. 2020. Seed biofortification by engineered nanomaterials: A pathway to alleviate malnutrition? Journal of Agricultural and Food Chemistry 68(44):12189–202. Derrien TL, Hamada S, Zhou M, Smilgies DM, Luo D. 2020. Three-dimensional nanoparticle assemblies with tunable plasmonics via a layer-by-layer process. Nano Today 30:100823. Díaz SA, Choo P, Oh E, Susumu K, Klein WP, Walper SA, Hastman DA, Odom TW, Medintz IL. 2021. Gold nanoparticle templating increases the catalytic rate of an amylase, maltase, and glucokinase multienzyme cascade through substrate channeling independent of surface curvature. ACS Catalysis 11:627–38. Dimkpa CO, Andrews J, Sanabria J, Singh U, Elmer WH, Gardea-Torresdey JL, White JC. 2020. Interactive effects of drought, organic matter, and zinc oxide nanoscale and bulk particles on wheat performance and grain nutrient accumulation. Science of the Total Environment 722:137808. Ellis GA, Díaz SA, Medintz IL. 2021. Enhancing enzymatic performance with nanoparticle immobilization: Improved analytical and control capability for synthetic biochemistry. Current Opinion in Biotechnology 71:77–90. Hamada S, Yancey KG, Pardo Y, Gan M, Vanatta M, An D, Hu Y, Derrien TL, Ruiz R, Liu P, and 2 others. 2019. Dynamic DNA material with emergent locomotion behavior powered by artificial metabolism. Science Robotics 4:eaaw3512. Han X, Ye Y, Lam F, Pu J, Jiang F. 2019. Hydrogen-bonding-induced assembly of aligned cellulose nanofibers into ultrastrong and tough bulk materials. Journal of Materials Chemistry A 7:27023–31. Hofmann T, Lowry GV, Ghoshal S, Tufenkji N, Brambilla D, Dutcher JR, Gilbertson LM, Giraldo JP, Kinsella JM, Landry MP, and 7 others. 2020. Technology readiness and overcoming barriers to sustainably implement nanotechnology-enabled plant agriculture. Nature Food 1:416–25. Kah M, Tufenkji N, White JC. 2019. Nano-enabled strategies to enhance crop nutrition and protection. Nature Nanotechnology 14:532–40. Kang H, Elmer W, Shen Y, Asunción PB, Zuverza-Mena N, Ma C, White JC, Haynes CL. 2021. Silica nanoparticle dissolution rate controls the suppression of Fusarium wilt of watermelon (Citrullus lanatus). Environmental Science and Technology 5(20):13513–22. Landenmark HKE, Forgan DH, Cockell CS. 2015. An estimate of the total DNA in the biosphere. PLoS Biology 13:e1002168. Lew TTS, Koman VB, Gordiichuk P, Park M, Strano MS. 2019. The emergence of plant nanobionics and living plants as technology. Advanced Materials Technologies 5:1900657. Li Y, Cu YTH, Luo D. 2005. Multiplexed detection of pathogen DNA with DNA-based fluorescence nanobarcodes. Nature Biotechnology 23:885–89. Li T, Zhang X, Lacey SD, Mi R, Zhao X, Jiang F, Song J, Liu Z, Chen G, Dai J, and 5 others. 2019. Cellulose ionic conductors with high differential thermal voltage for low-grade heat harvesting. Nature Materials 18:608–13. Li T, Chen C, Brozena AH, Zhu JY, Xu L, Driemeier C, Dai J, Rojas OJ, Isogai A, Wågberg L, Hu L. 2021. Developing fibrillated cellulose as a sustainable technological material. Nature 590:47–56. Ma C, Borgatta J, Hudson BG, Tamijani AA, De La Torre-Roche R, Zuverza-Mena N, Shen Y, Elmer WH, Xing B, Mason SE, and 2 others. 2020. Advanced material modulation of plant nutritional and phytohormone status suppresses soybean sudden death syndrome (SDS) and increases yield. Nature Nanotechnology 15:1033–42. Ostrovidov S, Shi X, Zhang L, Liang X, Kim S, Fujie T, Ramalingam M, Chen M, Nakajima K, Al-Hazmi F. 2014. Myotube formation on gelatin nanofibers–multi-walled carbon nanotubes hybrid scaffolds. Biomaterials 35:6268–77. Pandey K, Lahiani MH, Hicks VK, Hudson MK, Green MJ, Khodakovskaya M. 2018. Effects of carbon-based nanomaterials on seed germination, biomass accumulation and salt stress response of bioenergy crops. PLoS One 13(8):e0202274. Pardo YA, Yancey KG, Rosenwasser DS, Bassen DM, Butcher JT, Sabin JE, Ma M, Hamada S, Luo D. 2022. Interfacing DNA hydrogels with ceramics for biofunctional architectural materials. Materials Today 53:98–105. Park N, Um SH, Funabashi H, Xu J, Luo D. 2009. A cell-free protein producing gel. Nature Materials 8:432–37. Paudel S, Cerbu C, Astete CE, Louie SM, Sabliov C, Rodrigues DF. 2019. Enrofloxacin-impregnated PLGA nanocarriers for efficient therapeutics and diminished generation of reactive oxygen species. ACS Applied Nano Materials 2(8):5035–43. Schmidt C, Krauth T, Wagner S. 2017. Export of plastic debris by rivers into the sea. Environmental Science and Technology 51:12246–53. Scott NR, Chen H. 2003. Nanoscale Science and Engineering for Agriculture and Food Systems: Roadmap Report of National Planning Workshop. Washington: Cooperative State Research, Education, and Extension Service, US Department of Agriculture. Sharma S, Huang Z, Rogers M, Boutelle M, Cass AEG. 2016. Evaluation of a minimally invasive glucose biosensor for continuous tissue monitoring. Analytical and Bioanalytical Chemistry 408(29):8427–35. Shidore T, Zuverza-Mena N, White JC, da Silva W. 2021. Nanoenabled delivery of RNA molecules for prolonged antiviral protection in crop plants: A review. ACS Applied Nano Materials 4(12):12891–904. Takase M, Murata M, Hibi K, Huifeng R, Endo H. 2014. Development of mediator-type biosensor to wirelessly monitor whole cholesterol concentration in fish. Fish Physiology and Biochemistry 40(2):385–94. Um SH, Lee JB, Park N, Kwon SY, Umbach CC, Luo D. 2006. Enzyme catalyzed assembly of DNA hydrogels. Nature Materials 5:797–801. Wang A, Jin Q, Miao A, White JC, Gardea-Torresdey JL, Ji R, Zhao L. 2020a. High-throughput screening for engineered nanoparticles that enhance photosynthesis using mesophyll protoplasts. Journal of Agricultural and Food Chemistry 68(11):3382–89. Wang D, Cui J, Gan M, Xue Z, Wang J, Liu P, Hu Y, Pardo Y, Hamada S, Yang D, Luo D. 2020b. Transformation of biomass DNA into biodegradable materials from gels to plastics for reducing petrochemical consumption. Journal of the American Chemical Society 142:10114–24. Wang D, Byro A, Zepp R, Endalkachew S-D, Luxton TP, Ho KT, White JC, Flury M, Saleh NB, Su C. 2022. Nano-enabled pesticides for sustainable agriculture and global food security. Nature Nanotechnology 17:347–60. Wolfe KD, Gargye A, Mwambutsa F, Than L, Cliffel DE, Jennings GK. 2021. Layer-by-layer assembly of Photosystem I and PEDOT:PSS biohybrid films for photocurrent generation. Langmuir 37:10481–89. Xu T, Ma C, Aytac A, Hu X, Ng KW, White JC, Demokritou P. 2020. Enhancing agrichemical delivery and seedling development with biodegradable, tunable, biopolymer-based nanofiber seed coatings. ACS Sustainable Chemistry & Engineering 8(25):9537–48. Yao MF, Xiao H, McClements DJ. 2014. Delivery of lipophilic bioactives: Assembly, disassembly, and reassembly of lipid nanoparticles. Annual Review of Food Science and Technology 5:53–81. Yin S, Ibrahim H, Schnable PS, Castellano MJ, Dong L. 2021. A field-deployable, wearable leaf sensor for continuous monitoring of vapor-pressure deficit. Advanced Materials Technologies 6(6):2001246. Yurova N, Danchuk A, Mobarez S, Wongkaew N, Rusanova T, Baeumner AJ, Duerkop A. 2018. Functional electrospun nanofibers for multimodal sensitive detection of biogenic amines in food via a simple dipstick assay. Analytical and Bioanalytical Chemistry 410:1111–21. Zhang H, Goh NS, Wang J, Demirer GS, Butrus S, Park SJ, Landry MP. 2021a. Nanoparticle cellular internalization is not required for RNA delivery to mature plant leaves. Nature Nanotechnology 17:197–205. Zhang H, Cao Y, Xu D, Goh NS, Demirer GS, Chen Y, Landry MP, Yang P. 2021b. Gold-nanocluster-mediated delivery of siRNA to intact plant cells for efficient gene knockdown. Nano Letters 21(13):5859–66. [1] We do not discuss here the environmental and public health impacts associated with agrochemical exposure of nontarget organisms, pharmaceutical use in animal agriculture, or nutrient use in aquaculture. [2] Similar advances have been made in health and food sciences, where nanoparticle size and structure affect delivery and facilitate study of nutrient use across the digestive system (Yao et al. 2014). About the Author:Hongda Chen is national program leader, Bioprocess Engineering and Nanotechnology, National Institute of Food and Agriculture, US Department of Agriculture. Jason White is director, Connecticut Agricultural Experiment Station, with secondary appointments at Yale University and the University of Massachusetts. Antje Baeumner is professor and director, Institute of Analytical Chemistry, Chemo- and Biosensors, and dean, Faculty of Chemistry and Pharmacy, University of Regensburg. Dan Luo is a professor in the Department of Biological and Environmental Engineering, Cornell University.