J. Non-Crystalline Sol., 354, 2594-2597 (2008)
Conde, J. P., Pimentel, A. C., Pereira, A. T., GouvÍa, A., Prazeres, D. M. F., Chu, V.
A hydrogenated amorphous silicon micro-photodiode is used to optically detect the presence, in solution, of
species which can be used as molecular labels for biomolecules. These molecular labels are a fluorescent molecule
and an enzyme. The light emitted by the fluorophore (Alexa Fluor 430) in solution is detected by the photodiode
through an amorphous silicon carbon filter which absorbs the excitation light. The enzyme (horseradish
peroxidase) is used with two different substrates (luminol and tetramethylbenzidine) to produce chemiluminescent
and light absorbent products, respectively. Sensitivities down to picomolar level (corresponding to 1 attomole of
molecular labels in solution) have been obtained.
Keywords: amorphous silicon micro-photodiode; Alexa Fluor, HRP
|Back to: Publications||BioEngineering Research Group|