Affiliation:
1. Nanotechnology and Integrated Bioengineering Centre (NIBEC) School of Engineering Ulster University 2–24 York Street Belfast BT15 1AP UK
2. Healthcare Technology Hub School of Engineering Ulster University 2–24 York Street Belfast BT15 1AP UK
Abstract
AbstractUrine Specific Gravity (USG) is a direct indicator of the osmolarity of the urine and therefore it can be considered as a nonspecific marker of several underlying diseases which result in changes in hydration levels of the body. Here, a biosensor based on the principle of localized surface plasmon resonance (LSPR) is developed, which utilizes its refractive index sensing properties to measure USG with a sensitivity of 79.21 nm USG−1unit. Additionally, the sensor can measure the serum protein content within the urine. Traditionally, handheld refractometers are used to measure USG which are operated as calibrated refractive index scales rather than a sensor. A simple experiment demonstrating the advantage of a sensor over scale, with LSPR as the transduction method, is also conducted to highlight the enhanced sensitivity of a sensor over a scale. Finally, analysis of results with an unsupervised machine learning algorithm, principal component analysis (PCA), demonstrate the feasibility of automating or perhaps adding artificial intelligence to such sensors, thereby exemplifying a potential paradigm shift from refractive index scales to sensors in USG measurement.