Enhanced detection of neurotransmitters by depositing shape-specific gold nanoparticles onto carbon fiber microelectrodes

In vivo detection of neurotransmitters is a difficult process, but such detection offers vital data to tracking a patient’s progress through certain therapies. Using carbon fiber microelectrodes (CFMEs) has been verified as a cost-effective method to detect neurotransmitters for both in vivo and in vitro experimentation. However, bare CFMEs have some limitations as they are not sensitive enough to detect trace amounts of dopamine such as those found in a Parkinson’s Disease patient’s brain. Therefore, a more sensitive method is needed. It has been shown that gold nanoparticles (AuNPs) can be deposited onto CFMEs to enhance the detection sensitivity. However, only preliminary studies have been performed up to now and this can be further explored. In addition to spherical gold nanoparticles (AuNPs), a number of different shapes and sizes of AuNPs can be synthesized. Shapes such as cubes, octahedrons, rhombic dodecahedrons, rods, spheres, and prisms can enhance the sensitivity of detection in different ratios across various neurotransmitter metabolites by changing the surface of the sensor. The purpose of this research is to use shape-specific AuNPs modified CFMEs (AuNPs-CFMEs) to detect neurotransmitters, such as dopamine. We hypothesize that not only the chemical composition of the coating, but also the shape and surface roughness, can enhance neurochemical deposition. For this study, we have focused on preparing CFMEs coated with cubic, octahedral, and rhombic dodecahedral (RD) AuNPs. Nanoparticles are deposited onto the CFMEs using specific techniques. We plan to find the effect of specific AuNP morphologies, sizes, and uniformity on CFME sensitivity and detection using fast scan cyclic voltammetry (FSCV). Future considerations begin with the synthesis of other morphologies, such as nanorods, nano prisms, and nanospheres. Dopamine analogues, such as tyrosine, can also be considered as an aim for detection in the future.