A Tunable Plasmonic Refractive Index Sensor with Ultrabroad Sensing Range for Cancer Detection

Abstract

Contribution of quantum dots (QDs) and nano dots (NDs) in boosting the plasmonic behavior of noble metal nano cavity structure and its refractive index (RI) sensing is proposed across an ultrabroad RI range via first, second, and third near-infrared windows. An optimized refractive index sensor based on plasmonic-photonic interaction arising from the extraordinary optical transmission (EOT) through nano cavity is reported. Herein, the sensing platform comprised of an array of silver square nano disc and ring having cavity in between. By the introduction of dots, the absorption profile of entire system is dramatically modified resulting from the plasmon-exciton/plasmon-plasmon coupling and thereby attains higher tunability in sensing parameters together with an enhanced figure of merit (FOM), all confirmed by finite element method (FEM) stimulations. The tailorable hybrid structure demonstrating absorbance enhancement and resonant peak shift with cavity area, embedded material permittivity, presence of dots, etc., proposes an open platform for optical-based chemical and biosensing applications.