🇺🇸 Sirish Subash

Sirish Subash grew up in Snellville, Georgia, a suburb east of Atlanta, in a household where — as in millions of others — a parent's standing instruction was to wash fruits and vegetables before eating them.

Most children obey or ignore the instruction. Sirish investigated it. He wanted to know whether washing actually removed what it was supposed to remove, and the literature he found was unsettling: about 70 percent of produce items carry pesticide residues, which studies have linked to health problems including cancer and Alzheimer's disease.

The deeper problem was invisibility. A consumer has no way of knowing whether a given apple carries residue — no signal, no test, no feedback. Sirish reasoned that if people could detect residues, they could avoid consuming them, and washing could become verification rather than faith.

His answer was PestiSCAND, a handheld device that combines spectrophotometry — measuring how light reflects off a surface at different wavelengths — with a machine-learning model trained to recognize the spectral signatures of pesticide residues on produce.

The physics is elegant: pesticide residues alter how light bounces off the surface of a fruit or vegetable in ways invisible to the eye but measurable to a sensor. The AI does the interpretation, turning raw spectral data into a simple verdict a shopper can act on.

In tests on tomatoes, strawberries, spinach and other produce, Sirish reported detection accuracy above 85 percent — remarkable for a sensor assembled by a middle schooler with off-the-shelf components costing far less than laboratory equipment.

He entered the device in the 3M Young Scientist Challenge, one of America's premier middle-school science competitions, where finalists spend a summer developing their inventions with 3M scientist mentors before a final live judging.

In October 2024 the verdict came in: Sirish Subash was named America's Top Young Scientist, taking the $25,000 grand prize. Coverage from national outlets followed, framing his win the way he frames the device — as consumer empowerment.

He has been clear that PestiSCAND is a beginning rather than a trophy. He has spoken about refining the device toward a consumer price point around $20 and eventually bringing it to market, so that checking an apple for residues could become as routine as checking its price.

The 3M Young Scientist Challenge format shaped the device as much as the idea did. Each finalist is paired for a summer with a 3M scientist mentor who pushes the project through the discipline of real product development: defining specifications, testing against them, iterating on failure. By final judging, PestiSCAND had progressed from a science-fair concept to a working prototype defended before a panel of professional scientists — a compression of the engineering cycle most people first encounter in industry.

His design choices reveal an unusually commercial instinct for a fourteen-year-old. Spectrophotometry is a laboratory-grade technique, but Sirish built around affordable sensor components precisely because a device that costs thousands protects no one. The target he has spoken about — roughly $20 — is the difference between a demonstration and a product, and it is the detail that industry observers consistently flag in his coverage.

The problem he chose is stubbornly real. Regulatory monitoring of pesticide residues happens at the supply-chain level, through laboratory sampling — by the time results exist, the produce has been eaten. Washing helps but does not eliminate residues, and consumers have no verification step at all. A point-of-consumption detector, even an imperfect one, adds a feedback loop where none has ever existed.

Sirish joins a distinctly consequential cohort of Georgia and Southern teen inventors who have used the 3M Challenge as a launchpad — previous winners have gone on to patents, startups, and national research careers — and his win extended the striking run of Indian American students dominating America's premier youth science competitions across spelling, science, and mathematics alike.

What separates his story from the annual parade of clever science-fair devices is the theory of change embedded in it. Sirish has consistently framed PestiSCAND not as a gadget but as behavior modification through information: people wash produce more carefully when they can see the reason, the same way home water-testing kits changed how households treat their taps. It is a fourteen-year-old reasoning like a public health economist — the health outcome comes not from the sensor itself but from the millions of small decisions the sensor makes visible.

Sirish's trajectory — curiosity sparked at the kitchen sink, sharpened into an award-winning instrument — places him in a rising generation of American teen inventors who treat household problems as engineering briefs. The next reminder to wash your fruit may come with a reading.