A Portable Electrochemical Platform Integrated with a 3D AuNPs/CNTs Sponge for Point-of-Care Testing of Neurotransmitters

Point-of-care testing (POCT) of neurotransmitters, such as dopamine (DA) and 5-hydroxytryptamine (5-HT), can be used for early diagnosis of neurological diseases. Among various POCT platforms, electrochemical method-based platforms have attracted increasing interest owning to their high detection sensitivity and specificity as well as fast response time. In this work, we developed a portable electrochemical POCT platform for detection of neurotransmitters, which is based on integration of a three-dimensional (3D) gold nanoparticles/carbon nanotubes (AuNPs/CNTs) sponge synthesized by a simple in-situ growth and eco-friendly ice-templating method modified screen-printed electrode with a miniaturized USB electrochemical analyzer. We demonstrated the good performance of the portable electrochemical platform for detection of two typical neurotransmitters, i.e., DA and 5-HT, with detection sensitivities of 1.02 μA μM−1 cm−2 and 0.55 μA μM−1 cm−2, and detection limits of 0.06 μM and 0.30 μM for DA and 5-HT, respectively. We further verified the feasibility and practicability of the platform by simultaneous detection of DA and 5-HT in spiked saliva. The developed portable electrochemical platform provides a simple and user-friendly way for early diagnosis of neurological diseases in the future, especially at point of care.