Multiple protein‐patterned surface plasmon resonance biochip for the detection of human immunoglobulin‐G

Abstract

AbstractA portable surface plasmon resonance (SPR) measurement prototype integrated with a multiple protein‐patterned SPR biochip is introduced for label‐free and selective detection of human immunoglobulin‐G (H‐IgG). The polyclonal anti‐H‐IgG antibodies derived from goat, rabbit, and mouse were immobilized through polydimethylsiloxane (PDMS) microchannels to fabricate the patterned SPR biochip. The PDMS surface was functionalized using 3‐aminopropyltrimethoxysilane and bonded to carbodiimide‐activated gold substrates to construct irreversibly bonded hydrophilic microfluidic chip at room temperature. For SPR measurement, a custom‐made system is developed with a high angular scanning accuracy of 0.005° and a wide scanning range of 30°–80° that avoids the conventional requirement of expensive goniometric stages and detector arrays. The SPR biochip immobilized with 750 μg/mL goat anti‐H‐IgG demonstrated detection of H‐IgG with a detection limits of 15 μg/mL, and linear response through a wide concentration range (15–225 μg/mL) of high coefficient of determination (R2 = 0.99661). The selectivity of the sensor was investigated by exposing them to two different non‐specific targets (bovine serum albumin and polyvalent antivenom). The results indicate negligible sensor response towards nonspecific targets (0.25° for 30 μg/mL bovine serum albumin (BSA) and 0.25° for 30 μg/mL polyvalent antivenom) in comparison to H‐IgG (1.5° for 30 μg/mL).