Magnetically boosted light-driven hydrogel microrobots for ultrasensitive and fast detection of PFOS distribution in unprocessed urine, bile, and whole blood

Monitoring biofluids involved in the circulation of pollutants after entering the body is crucial for determining their physical burden and investigating metabolic processes and health risks associated with exposure to these pollutants. Considering the complexity and high viscosity of biofluids, we herein developed magnetically boosted light-driven hydrogel microrobots (HMRs) that exhibit excellent antifouling ability and satisfactory motion speeds of 204, 176, and 92.5 μm/s in unprocessed urine, bile, and whole blood for overcoming sensor passivation and facilitating the mass transfer and target perfluorooctane sulfonic acid (PFOS) recognition. PFOS is an emerging persistent organic pollutant that is ubiquitous worldwide and may lead to many serious diseases. The HMRs-based electrochemical sensor enables fast (5 min) and ultrasensitive detection of PFOS in urine, bile, and whole blood with detection limits of 0.0147, 0.0155, and 0.0179 fg/mL, respectively. Through the detection of biofluids at different stages after PFOS ingestion, it is found that PFOS mainly circulates in blood and small amounts are excreted through bile and urine, which intuitively confirms that PFOS in the body is difficult to eliminate and helpful for understanding its health threat. Finally, the initial attempt at in-situ detection of intravascular PFOS demonstrates HMRs' future potential in the in-vivo monitoring field.