Molecular Sensing System Based on Multi-Technologies Architecture

Considering the difficulty of measuring neurotransmitters in the field of biomedical research, a portable autonomous sensing and analysis system of neurotransmitters is needed. This type of device would improve the diagnostics of neurodegenerative diseases such as Alzeimer, Parkinson, Huntington diseases. Thus, in this work, we present a synthesis research paper to describe our device capable of measuring neurotransmitters in a liquid sample using functionalized ultrastable gold nanoparticles.(1-4) It uses a colorimetric sensor to measure neurotransmitter indirectly. Indeed, using the colorimetric sensing approach, the plasmonic resonance band of nanoparticles shifts when they interact with neurotransmitters. The functionalization of the nanoparticles with dopamine-specific aptamer increases the response and selectivity towards the neurotransmitter of interest. Also, using ultrastable gold nanoparticles(5) provides the potential to expose them to harsh conditions without agglomeration. Those harsh conditions includes the presence of salts that would otherwise compromise the efficiency of the sensing as well as conditions that are used to wash and clean the solutions (freeze drying, heating, ultracentrifugation and autoclaving). By being able to resist to those types of conditions, it gives the potential to recycle the nanoparticles to be reused for several sensing cycles. This sensing system uses a grism-based spectrometer design for the colorimetric analysis of neurotransmitters covering a bandwidth of 420 to 620 nm. Moreover, the system includes a microfluidic module for the manipulation of samples as well as an electronic module for data acquisition and analysis. Altogether, the system showed that the absorption spectrum of a nanoparticles sample with a resolution of 0.7 nm can be extracted autonomously using this system.