Nanobiotechnology has ushered in a new era of scientific discovery where the unique properties of nanomaterials, such as gold nanoparticles, have been harnessed for a wide array of applications. This review explores gold nanoparticles’ synthesis, properties, and multidisciplinary applications, focusing on their role as biosensors. Gold nanoparticles possess exceptional physicochemical attributes, including size-dependent optical properties, biocompatibility, and ease of functionalization, making them promising candidates for the development of biosensing platforms. The review begins by providing a comprehensive overview of gold nanoparticle synthesis techniques, highlighting the advantages and disadvantages of various approaches. It then delves into the remarkable properties that underpin their success in biosensing, such as localized surface plasmon resonance and enhanced surface area. The discussion also includes the functionalization strategies that enable specific binding to biomolecules, enhancing the sensitivity and selectivity of gold-nanoparticle-based biosensors. Furthermore, this review surveys the diverse applications of gold nanoparticles in biosensing, encompassing diagnostics, environmental monitoring, and drug delivery. The multidisciplinary nature of these applications underscores the versatility and potential of gold nanoparticles in addressing complex challenges in healthcare and environmental science. The review emphasizes the pressing need for further exploration and research in the field of nanobiotechnology, particularly regarding the synthesis, properties, and biosensing applications of gold nanoparticles. With their exceptional physicochemical attributes and versatile functionalities, gold nanoparticles present a promising avenue for addressing complex challenges in healthcare and environmental science, making it imperative to advance our understanding of their synthesis, properties, and applications for enhanced biosensing capabilities and broader scientific innovation.

The adsorption of rhodamine B (RhB) using acid modified banana peels has been examined. Chemical characteristics of the adsorbents were observed in order to determine active functional groups. The major functional groups on the surface were OH, C = O, C = C and C-O-C. Interactions between operational parameters were studied using the central composite design (CCD) of response surface methodology (RSM). The predictions of the model output indicated that operational factors influenced responses at a confidence level of 95% (P<0.05). The optimum conditions for adsorption were pH 2 at a 0.2 g/L dose within 60 minutes of contact time. Isotherm studies were carried out using the optimized process variables. The data revealed that RhB adsorption fitted the Langmuir isotherm equation while the reduction of COD followed the Freundlich isotherm. Kinetic experiments fitted the pseudo second order model for RhB removal and COD reduction. The adsorption mechanism was not the only rate controlling step. Diffusion through the boundary layer described the pattern of adsorption.