In situ formed silicon-based nanoparticles enabled highly efficient dual-mode biosensing of chlorpyrifos

Chlorpyrifos is widely used in agriculture but their residue is a threat to food safety and human health. The study aims to find an accurate and sensitive detection method for chlorpyrifos. Silicon-based nanoparticles (Si BNPs) with fluorescent and colorimetric dual signals are in-situ formed through the alkaline phosphatase (ALP) trig-gered reaction. The dual-mode sensor for chlorpyrifos can be facilely fabricated because the existence of chlorpyrifos would inhibit the activity of ALP and thus affect the production of Si BNPs. Under optimal condition, the fluorescence intensity and absorption intensity linearly correlate with the logarithm of chlorpyrifos con-centration over wide range of 0.5-5000 ng/mL and 1-5000 ng/mL with low detection limit by the two detection modes, respectively. The dual-mode sensor is further applied to the detection of spiked chlorpyrifos in practical samples with satisfactory recovery, rendering it as a promising candidate to current methodologies for the simple and accurate detection of chlorpyrifos.