Redox cycling for an in-situ enzyme labeled immunoassay on interdigitated array electrodes

Interdigitated array electrodes;Redox cycling;4-Aminophenol;B-Galactosidase;Comb IDA;Microchannels;Paramagnetic beads

Kim, Sangkyung ; Biomedical Engineering

University:Georgia Institute of Technology

Department:Biomedical Engineering

关键词: Interdigitated array electrodes;    Redox cycling;    4-Aminophenol;    B-Galactosidase;    Comb IDA;    Microchannels;    Paramagnetic beads;   

Others  :  https://smartech.gatech.edu/bitstream/1853/4790/1/kim_sangkyung_200412_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

This research is directed towards developing a more sensitive and rapid electrochemical sensor for enzyme labeled immunoassays by coupling redox cycling at interdigitated electrode arrays (IDA) with the enzyme label b-galactosidase. Coplanar and comb IDA electrodes with a 2.4 mm gap were fabricated and their redox cycling currents were measured. ANSYS was used to model steady state currents for electrodes with different geometries. Comb IDA electrodes enhanced the signal about 3 times more than the coplanar IDAs, which agreed with the results of the simulation. Magnetic microbead-based enzyme assay, as a typical example of biochemical detection, was done using the comb and coplanar IDAs.The enzymes could be placed close to the sensing electrodes (~10 mm for the comb IDAs) and detection took less than 1 min with a limit of detection of 70 amole of b-galactosidase. We conclude that faster and more sensitive assays can be achieved with the comb IDA. A paramagnetic bead assay has also been demonstrated for detection of bacteriophage MS2, used as a simulant for biothreat viruses, such as small pox.The immunoassay was carried out in a microfluidic format with the IDA, reference and counter electrodes integrated on the same chip.Detection of 90 ng/mL MS2 or 1.5x1010 MS2 particles/mL was demonstrated.