Hu et al. (2025) develop a whole-cell biosensor integrating Bacillus megaterium bacteria with complementary metal-oxide-semiconductor (CMOS) electronics for arsenic detection. The system is specifically calibrated to detect total arsenic at or below the US EPA maximum contaminant level (MCL) of 10 ppb for drinking water, and the authors demonstrate applicability to both soil and food matrices.
Key numbers
Detection threshold: below 10 ppb (µg/L or µg/kg) for total arsenic (tAs). The CMOS integration allows electronic signal processing for quantitative output. The claim of applicability to “soil and food” matrices distinguishes this from purely water-matrix biosensors.
Note: this detects total arsenic (tAs), not inorganic arsenic (iAs). The iAs/tAs distinction is non-negotiable for food regulatory compliance (FDA CTZ uses iAs for infant rice cereal), but tAs measurements remain valuable as an initial screening step.
Methods (brief)
Whole-cell biosensor (B. megaterium arsenic-responsive promoter) integrated with CMOS chips for electronic signal readout. Food and soil matrix validation. LOD at or below 10 ppb total arsenic. The combination of a biological recognition element with CMOS integration represents a step toward miniaturized, field-deployable arsenic screening devices for food applications.
Implications
Testing: Applicability to food matrices is the key feature. Most whole-cell biosensors for arsenic have been validated only in water. If the food matrix validation is robust (sufficient sample preparation to remove interferents), this could be a useful screening tool for high-arsenic ingredients like rice, seaweed, or root vegetables. However, speciation (iAs vs. organic As) is not possible with this platform; positive screens would require ICP-MS speciation confirmation.