Executive Summary : | Early-stage disease detection is crucial for detecting dangerous diseases, as protein markers in bodily fluids are typically in the order of femto Molar (fM) and have a size smaller than 30 nm. Detecting protein markers at ultralow concentrations is difficult and requires ultra-high resolution and unparalleled sensitivity biosensors. Nanoplasmonic-whispering gallery mode hybrid devices are useful for real-time detection of single protein molecules in aqueous media encapsulated in a microfluidic channel. These hybrid devices consist of a whispering gallery mode microresonator and a nanoplasmonic resonator. The detection is demonstrated by monitoring the shift in resonance wavelength upon adsorbing single protein markers at the active sites of the hybrid devices. Based on the response of these optofluidic hybrid devices, one can estimate the size, mass/molecular weight of protein molecules. However, these hybrid devices have been used only as detectors and reported non-specific detection of single molecules. To address this, the current project focuses on fabricating efficient optofluidic hybrid devices, converting them into biosensors with suitable antibodies, and demonstrating specific detection of single protein molecules in real-time using the fabricated OHBs. |