CMOS and MEMS based micro hemoglobin-A1c biosensors fabricated by various antibody immobilization methods

This paper presents a micro multichannel immunosensor for hemoglobin-A1c level determination rapidly and conveniently. The micro immunosensor is composed of an integrated FET sensor chip and a disposable microelectrode-array chip based on CMOS and MEMS technique, respectively. Antibody immobilization methods, such as mixed self-assembled monolayers (SAMs), seed mediated growth nano-gold and nano-gold wrapped with mixed SAMs are studied. The immunosensor fabricated by nano-gold wrapped with mixed SAMs immobilization method shows the highest sensitivity due to the uniform distribution of the nano-golds without aggregation, and the increase of biomolecules amount on the sensitive area of the micro electrode chip. Whole blood samples obtained from hospital were examined using this immunosensor. Relative standard deviation of 2.63% and recovery of 102.54% were achieved.