Alex Constantine - March 21, 2008
Functionalized Nanoparticle Based Biosensor Description
From the Inframat web site
Inframat is in the process of developing two types of nanostructured biosensors, including ... bioconjugated nanoparticle based biosensors for neurotransmitter detection applications.
... Nanoparticle based neurotransmitter sensors: Gamma-aminobutyric acid (“GABA”) is a main mammalian nervous system inhibitory neurotransmitter, playing important roles in neural function and dysfunction. Accurate real time measurement of GABA will greatly accelerate discoveries on the key role of GABA in motor disorders including Huntington’s disease and Parkinson’s, seizures, myoclonic discharges, and alcohol addiction. Accurate assessment of changes in its extracelluar content on-line, in relatively short time-spans, would lead to a better understanding of its functions. GABA is insensitive to ultra-violet (UV)-visible spectroscopic determination methods. Current technologies for extracellular measurement of GABA focus on microdialysis of the cerebro-spinal fluid, followed by liquid chromatography combined with pre-/post column derivatization. Liquid chromatography-based measurements are not continuous, while microdialysis itself is an invasive procedure that causes neuronal death and reactive gliosis and has very poor spatio-temporal resolution. Also, direct electrochemical monitoring of extracellular GABA in the brain is very difficult because a specific active enzyme capable of generating a redox species does not exist for GABA.
Inframat is currently exploring novel functionalized biomaterials to dramatically improve biosensor response in high sensitivity detection for neurotransmitter applications, via a “competitive enzyme immunoassay” strategy, to electrochemically measure non-electroactive GABA neurotransmitter concentrations. This technology (1) adopt IMC’s economically viable wet chemical synthesis technique to produce antibody-linked biocompatible nanomaterials, (2) immobilize functionalized nanoparticles onto transducers to produce high sensitivity biosensors for real time monitoring of GABA concentrations in a PBS buffered solution, and (3) enable in-vitro testing of the biosensor based functionalized nanoparticles in artificial cerebro-spinal fluid (CSF). This is the first time that an antibody-conjugated nanoparticle based approach is being attempted for GABA determination. This approach will enable biosensors continuous and direct measurement of GABA concentrations, and can also be extended to multiple channels to obtain a spatial-temporal distribution in a brain slice and cell culture preparations. The development of this selective, sensitive, and rapidly responding GABA electrochemical immunomicroprobe will make it possible to measure dynamic events associated with GABA neurotranmission in the central nervous system, and the establishment of a GABA microprobe capability to monitor the component of the basal extracellular GABA level derived from brain tissue neuronal activities.