ABSTRACT
Nanomaterials and light emitting radiating dipoles (LERDs) have found widespread use in technological revolution with immense utility in photoplasmonic based sensor applications. Since the onset of the millennium, surface plasmon-coupled emission (SPCE) is being increasingly explored to achieve highly polarized, low background noise, high spectral resolution, sharply directional emission, and ultra-sensitive biosensing platforms. The radiative decay lifetime of LERDs has been engineered with a variety of nanohybrids: Ag−SiO2, Ag−GO, Ag−Nd2O3, Ag−protein, TiO2−GO, Pd−Ag, TiCN−GO, AgAu and soretnanoassemblies to understand their plasmonic and waveguide response and nanostructure−activity relationship in spacer, cavity, and extended-cavity nanointerfaces in order to realize tunable first-, second-, and third-generation ‘hotspots’. Recently, scientists have strategized novel materials’ chemistry approaches to develop alternative biosensing platforms such as photonic crystal-coupled emission (PCCE) and graphene oxide plasmon-coupled soliton and plasmon (GraSP) emission platform, which significantly enhances the performance of LERDs and in turn the sensitivity of related biosensing frameworks. These pioneering works with the next-gen photo-plasmonic coupling of LERDs and nanoengineered surfaces has resulted in unprecedented 1000-fold enhancements in the emission from LERDs. These unified principles have been explored with different nanomaterials spanning metal, dielectric, graphene-π-plasmon, and their hybrids via novel approaches for sensing diverse analytes: tannic acid, spermidine, cysteine, glutathione, aluminum, zinc, copper and mercury ions at pico, femto, atto, and zepto molar concentrations. While there are different technologies for improving the performance of LERDs, this chapter focuses on the utility of frugal and disruptive engineering of nanohybrids in SPCE and PCCE platforms for realizing efficient light extraction from LERDs for sensing applications. The obtained emission was captured using economical, user-friendly smartphone-based platform and the extracted luminosity values are in excellent correlation with the data obtained from high cost cumbersome conventional detectors. The platforms elaborated in this chapter are robust for biosensing, especially in resource-limited settings.
