A multiple reflection attenuated total reflectance sensor incorporating a glass-indium tin oxide surface modified via direct attachment or film encapsulation of colloidal gold nanoparticles

作者：Weikel AL; Conklin SD; Richardson JN^*

来源：Sensors and Actuators B: Chemical , 2005, 110(1): 112-119.

DOI：10.1016/j.snb.2005.01.017

• glass-indium tin oxide
• nanoparticle
• surface plasmon resonance

This paper outlines improvements in sensitivity and detection limit for an optical sensor based on measurement of change in the surface plasmon resonance (SPR) absorbance of substrate-confined colloidal Au nanoparticles. Two routes were taken to obtain these improvements. First, a thin-layer, multiple internal reflection flow cell that allows for simultaneous potential control of the sensing surface was employed. This cell geometry yielded a ca. 18-fold increase in sensitivity to changes in bulk refractive index compared to a similar, previously reported sensor employing a single pass incident beam. Our second improvement involves preconcentration and encapsulation of colloidal Au nanoparticles into a quaternized poly(4-vinylpyridine) (QPVP) cationic exchange film spin-coated onto the glass-indium tin oxide (ITO) substrate surface. We demonstrate that the encapsulated nanoparticles retain their SPR activity; this approach therefore represents a novel and simple method of preparing a highly sensitive nanoparticle-based SPR sensing surface.

• 出版日期2005-9-30