Immobilized Molecules’ Impact on the Efficacy of Nanocarbon Organic Sensors for Ultralow Dopamine Detection in Biofluids

Abstract

AbstractDopamine (DA) is a key neurotransmitter that regulates many behaviors and physical functions in the human body. Therefore, there is a significant technological demand for an affordable point‐of‐care (POC) device to monitor low DA levels up to 10−12min human biofluids. This can be achieved if the underlying interaction mechanism of analyte– materials–transduction is tuned at the molecular level in the carbon‐based organic sensors, and such knowledge is deficient in current literature. Herein, the one‐step facile molecular engineering approach is adopted to develop three organic‐based sensors consisting of different arylamines (hydroxyl/carboxyl/sulfonate) anchored to the surface of 2D‐reduced graphene oxide (rGO). The impact of immobilized molecules on their efficacy is studied in detail by experimental and computational approaches. The carboxyl–arylamine attached to rGO surface outperforms others, resulting in the detection of DA up to 10 × 10−12m(at a larger linear range of 10−10–10−4m) in the presence of interferents. As a proof of concept, a POC device is designed and evaluated in serum, artificial sweat, and urine samples, exhibiting exceptional results. The rational understanding and fundamental science behind the tunable features of carbon‐based organic sensors presented in this work will enable the development of innovative probes for detecting neurotransmitters and related biomolecules.