Antibody Sensors Race to Catch Pesticides and Fungal Toxins in Our Food

Every year, the World Health Organization estimates that roughly 600 million people fall ill after eating food contaminated with chemicals or pathogens, and about 400,000 die from unsafe food. Two of the most stubborn culprits lurking in fruits, vegetables, and cereals are pesticide residues and mycotoxins, the toxic secondary metabolites produced by fungi such as Aspergillus, Fusarium, Penicillium, and Alternaria. A new narrative review published in Food Chemistry: X takes a sweeping look at how antibody-based sensing technologies, including ELISA, lateral-flow immunoassays, and immunosensors, are being deployed to catch these contaminants quickly, cheaply, and accurately before they reach consumers.

The scale of the contamination problem is staggering. The Food and Agriculture Organization has long estimated that about 25 percent of food crops are tainted with mycotoxins, but more recent analyses suggest the true figure may be as high as 60 to 80 percent, a revision driven largely by improvements in analytical sensitivity. On the pesticide front, roughly 3.73 million tonnes of agricultural chemicals were applied globally in 2023, yet only an estimated 0.1 percent of pesticides actually reach their intended targets. The rest disperses into air, water, and soil, eventually threading its way back into the food chain and onto our plates.

The health stakes are far from theoretical. Organophosphate pesticides such as chlorpyrifos, diazinon, and malathion can inflict long-term neurological and psychiatric damage by inhibiting the acetylcholinesterase enzyme. Paraquat exposure is linked to severe skin burns, pulmonary fibrosis, and respiratory failure, while carbamates like carbofuran have been associated with endocrine disruption, reproductive harm, and elevated risk of non-Hodgkin lymphoma. Mycotoxins, including aflatoxins, ochratoxin A, deoxynivalenol, and zearalenone, cause both acute and chronic toxicity and have been detected at alarming rates in staple grains worldwide.

The evidence from market surveys is sobering. In Turkish cereal products, aflatoxin B1 concentrations exceeded regulatory limits in more than a quarter of tested samples. In Pakistan, a study of 229 retail cereal products found that 130 were contaminated with zearalenone, 121 with aflatoxin B1, and 115 with ochratoxin A, with many samples breaching maximum permissible levels. In India, 70 of 117 cereal samples tested positive for zearalenone, and one-third of those exceeded European Union limits. Meanwhile, European Rapid Alert System data show that fruits and vegetables accounted for 67.1 percent of all pesticide residue notifications between 1999 and 2022, with okra, chili peppers, beans, and aubergines showing the highest contamination rates.

Against this backdrop, conventional analytical techniques such as gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry remain the gold standard for accuracy and sensitivity. But they come with serious drawbacks: they are time-consuming, demand toxic organic solvents, require expensive equipment and trained personnel, and are poorly suited to on-site or high-throughput screening. This is precisely the gap that antibody-based sensing platforms are engineered to fill, leveraging the exquisite molecular specificity of antigen-antibody interactions to deliver rapid results with minimal infrastructure.

ELISA, or enzyme-linked immunosorbent assay, has emerged as one of the most versatile of these platforms. Competitive ELISA formats dominate for small-molecule contaminants such as pesticides and mycotoxins, which lack the multiple epitopes needed for sandwich-style detection. Recent innovations are striking. An indirect competitive ELISA developed for the neonicotinoid pymetrozine achieved detection limits between 1.62 and 1.66 micrograms per kilogram in wheat, maize, and rice, matching the sensitivity of liquid chromatography-tandem mass spectrometry at a fraction of the cost and time. Similarly, a direct competitive ELISA for the herbicide metsulfuron-methyl reached an IC50 of 37.03 micrograms per liter with recovery rates between 81 and 102 percent in spiked cereal samples.

Lateral-flow immunoassays, the same technology behind at-home pregnancy tests, push accessibility even further. These paper-based strips deliver visual results in minutes without instrumentation, making them ideal for farm, warehouse, or border-inspection settings. The review highlights how nanomaterial labels, particularly gold nanoparticles, have transformed LFIA performance. A gold nanoflower-based LFIA for the herbicide acifluorfen achieved a detection limit of 7.79 nanograms per milliliter, 9.6 times lower than a conventional gold nanoparticle version. Time-resolved fluorescent microsphere-based LFIAs have pushed limits even lower, detecting the fungicide paclobutrazol at 1.72 nanograms per milliliter and providing results within 18 minutes for triadimefon residues in oranges, tomatoes, and cucumbers.

Immunosensors represent the most technologically sophisticated end of the antibody-sensing spectrum, coupling immunochemical recognition to electrochemical, optical, or microgravimetric transducers. Electrochemical formats dominate because they offer high sensitivity, portability, and low cost. A graphene oxide-decorated screen-printed electrode immunosensor detected aflatoxin B1 in wheat flour at an astonishing 1.26 femtograms per microliter. A smartphone-based magneto-immunosensor for the same toxin in corn extract achieved a detection limit of 24 picograms per milliliter, displaying results in a simple traffic-light format through a companion Android app. Nanobody-mediated FRET immunosensors have detected ochratoxin A in rice, barley, wheat, and oats within five minutes at sub-microgram-per-kilogram limits.

Despite these advances, significant hurdles remain. Matrix effects, in which naturally occurring compounds in fruits, vegetables, and cereals such as enzymes, lipids, pigments, and sugars interfere with the analytical signal, continue to plague antibody-based methods, causing signal suppression or enhancement that undermines accuracy. Researchers are countering this through optimized extraction protocols, including QuEChERS pretreatment, hexane cleanup, and careful buffer selection. Antibody stability during storage and repeated freeze-thaw cycles poses another challenge, with aggregation and denaturation eroding performance over time. Camelid-derived nanobodies offer a promising solution, retaining functionality at temperatures as high as 40 degrees Celsius where conventional antibodies would fail, making them especially valuable for on-site applications in resource-limited settings.

Looking ahead, the review points toward a hybrid future in which artificial intelligence amplifies the reach of antibody-based sensing. Connectionist machine learning models excel at extracting subtle patterns from raw sensor data, while symbolic AI frameworks provide the transparent, rule-based reasoning needed for regulatory compliance and traceability across food supply chains. Integrating smartphone readers, cloud connectivity, and AI-driven interpretation with LFIA and immunosensor platforms could automate result analysis, minimize human error, and enable real-time remote monitoring. As contamination pressures mount under climate change and intensifying agriculture, these antibody-powered technologies are poised to become an indispensable frontline defense in keeping the global food supply safe.

Subject of Research: Antibody-based biosensing technologies for detecting pesticide residues and mycotoxins in plant-derived foods

Article Title: Antibody-based sensing of pesticide residues and mycotoxins in plant-derived foods: A narrative review of ELISA, lateral-flow immunoassays and immunosensors

Article References: Kumar, H., Guleria, S., Peter, L., Akhtar, N., Asghar, R., Harun, H. B. C., Kumar, D., Kuča, K., Shaikh, A. M., Harsányi, E., & Kovács, B. (2026). Antibody-based sensing of pesticide residues and mycotoxins in plant-derived foods: A narrative review of ELISA, lateral-flow immunoassays and immunosensors. Food Chemistry: X, Article 104530. https://doi.org/10.1016/j.fochx.2026.104530

Image Credits: AI Generated

DOI: 10.1016/j.fochx.2026.104530

Keywords: ELISA, lateral-flow immunoassay, immunosensors, pesticide residues, mycotoxins, food safety, biosensors, nanoparticles, cereals, fruits and vegetables, nanobodies, food contamination