Automated microarray technology for biomedical and environmental sensors.

by Aguilar, Zoraida P.; Nguyen, Chien Van; Sirisena, Mali; Gertsch, Jana; Arumugam, Prabhu; Spencer, Daryl; Wansapura, Chamika; Aguilar, Ysmael; Homesley, Jerry

Studies toward the development of automated, rapid, sensitive, low-cost, and reliable biomedical and environmental assays using arrays of microcavities with three individually addressable electrodes is reported. Each microcavity in the array contains a bottom electrode called recessed microdisk electrode (or RMD), a middle layer electrode found along the wall called tubular nanoband electrode (or TNB), and a rim/top electrode. The microelectrode TNB was used to detect the signal from a microwell assay for as low as 100 pg of Plasmodium falciparum CSP gene over 5-min enzyme substrate incubation. A self-contained microelectrochem. assay for Cryptosporidium parvum was generated using the RMD for capture, the TNB as the detecting electrode, and the rim/top as the pseudoreference/auxiliary electrodes. The 4- µm distance of the capture surface to the TNB detecting electrode provided close proximity to the assay components which allowed for a rapid response where the first signal was recorded within 30 s of enzyme substrate incubation. The self-contained nature of the microcavity provided low cost assays with the use of reagents down to 200 nL. The self-contained microelectrochem. microarrays were compatible with automation that was demonstrated in the detection of 25 pg Bacillus anthracis anti-PA IgG in < 25 min total assay time.

Journal
ECS Transactions
Volume
3
Issue
10
Year
2006
Start Page
125-137
URL
https://dx.doi.org/10.1149/1.2357253
ISBN/ISSN
1938-6737; 1938-5862
DOI
10.1149/1.2357253