We present a novel method for antibodies immobilization to fabricate a percent hemoglobin-A1c micro immunosensor. Nano-gold which is introduced by a novel seed mediated growth method is used for a micro potentiometric immunosensor of hemoglobin-A1c (HbA1c). To eliminate the nonspecific sites, nano-gold is capped with mixed self-assembled monolayers (MSAMs) to immobilize the antibodies stably and efficiently. This biomimetic layer preparation method has been applied firstly for modifying micro extended gate electrode array of biologically sensitive field-effect-transistor (BioFET). And combining with standard CMOS and MEMS techniques, this immunosensor exhibited high sensitivity, good stability, and achieved multichannels detection.