In situ biosynthetic-driven fluorescence sensor combined with a smartphone platform for portable detection of glyphosate

Glyphosate, a broad-spectrum herbicide extensively applied in agriculture, may bioaccumulate in humans via the food chain and pose toxicological risks. In this work, an integrated biosensing strategy for glyphosate is developed, integrating a self-developed Android application (APP) with alkaline phosphatase (ALP)-triggered silicon nanodot (Si NDs) fluorescence biosensing to achieve field-deployable quantification. In the sensing system, ascorbic acid (AA), produced by ALP-catalyzed substrate 2-phospho- l -ascorbic acid trisodium salt (AA2P), can reduce the silane precursor 3-aminopropyltrimethoxysilane (APTMS) at room temperature to nucleate and grow green fluorescent Si NDs with an emission wavelength of 505 nm. The fluorescence intensity is dynamically modulated by the inhibitory effect of glyphosate on ALP activity, enabling a quantitative relationship between pesticide concentration and signal output. The sensor displayed a robust linear response toward glyphosate across 0.005–100 μM, with detection limits of 2.4 nM (fluorimeter) and 18 nM (APP). Importantly, the custom-designed Android application integrates image acquisition, RGB signal extraction, and calibration modeling, transforming smartphone into portable analytical devices. This synergy between nanomaterial innovation and digital technology not only delivered high recovery rates (80–109.5%) in spiked real samples but also demonstrated excellent reproducibility (RSD < 2.9%) and selectivity, underscoring its promise as a next-generation strategy for on-site glyphosate monitoring.