文摘
Molecularly imprinted polymer gel with embedded goldnanoparticle was prepared on a gold substrate of a chipfor a surface plasmon resonance (SPR) sensor for fabricating an SPR sensor sensitive to a low molecular weightanalyte. The sensing is based on swelling of the imprintedpolymer gel that is triggered by an analyte binding eventwithin the polymer gel. The swelling causes greaterdistance between the gold nanoparticles and substrate,shifting a dip of an SPR curve to a higher SPR angle. Thepolymer synthesis was conducted by radical polymerization of a mixture of acrylic acid, N-isopropylacrylamide,N,N'-methylenebisacrylamide, and gold nanoparticles inthe presence of dopamine as model template species ona sensor chip coated with allyl mercaptan. The modifiedsensor chip showed an increasing SPR angle in responseto dopamine concentration, which agrees with the expected sensing mechanism. Furthermore, the gold nanoparticles were shown to be effective for enhancing thesignal intensity (the change of SPR angle) by comparisonwith a sensor chip immobilizing no gold nanoparticles.The analyte binding process and the consequent swellingappeared to be reversible, allowing one the repeated useof the presented sensor chip.