Recent advances in nanomaterials based biosensors for point of care (PoC) diagnosis of Covid-19 - A minireview.

Early diagnosis and ultrahigh sample throughput screening are the need of the hour to control the geological spread of the COVID-19 pandemic. Traditional laboratory tests such as enzyme-linked immunosorbent assay (ELISA), reverse transcription polymerase chain reaction (RT-PCR) and computed tomography are implemented for the detection of COVID-19. However, they are limited by the laborious sample collection and processing procedures, longer wait time for test results and skilled technicians to operate sophisticated facilities. In this context, the point of care (PoC) diagnostic platform has proven to be the prospective approach in addressing the abovementioned challenges. This review emphasizes the mechanism of viral infection spread detailing the host-virus interaction, pathophysiology, and the recent advances in the development of affordable PoC diagnostic platforms for rapid and accurate diagnosis of COVID-19. First, the well-established optical and electrochemical biosensors are discussed. Subsequently, the recent advances in the development of PoC biosensors, including lateral flow immunoassays and other emerging techniques, are highlighted. Finally, a focus on integrating nanotechnology with wearables and smartphones to develop smart nanobiosensors is outlined, which could promote COVID-19 diagnosis accessible to both individuals and the mass population at patient care.

Effects of Intralipid-10% in fluorescence distortion studies on liquid-tissue phantoms in UV range.

In biomedical optical spectroscopy tissue-mimicking phantoms have been widely used for imitating optical properties of biological tissues. As tissue is a turbid medium involving scatterers, absorbing and fluorescing molecules, modelling a tissue in the form of a phantom should have the same realistic complexity comparable to that of tissues. In optical spectroscopy, fluorescence phenomena have been extensively investigated as an optical technique for disease diagnosis. The fluorescence signal is distorted by optical properties of a biological tissue. The purpose of this study is to investigate whether the use of Intralipid as a scattering agent in a turbid medium containing fluorophores can affect fluorescent intensity by the phenomena of scattering and collisional quenching. The results indicate that phantom sets with different concentrations of Tyrosine and Intralipid have their emission peaks distorted at 300 nm and also show secondary peaks when used for fluorescence studies in UV region.