ABSTRACT
Currently, the development of biosensors is an urgent need due to the rapid spread of SARS-CoV-2 and the limitations of current standard methods for the diagnosis of COVID-19. Hence, many researchers have focused on the design of high-performance biosensors for measuring coronavirus genes. In this study, a voltammetric genosensor was developed for the determination of SARS-CoV-2 RdRP gene based on the format of cDNA probe/Au@CD core-shell NPs/graphite nanocrystals (GNCs)/paper electrode. For the first time, graphite nanocrystals were used in the electrochemical biosensor design. This genosensor was exposed to different concentrations of virus gene and then the hybridization between cDNA probe and RdRP gene was monitored by redox-active toluidine blue (TB). With increasing the RdRP concentration, the reduction peak current of TB enhanced in a linear range of 0.50 pM-12.00 nM according to the regression equation of I (µA) = 7.60 log CRdRP (pM) + 25.78. The repeatability with a RSD of 2.2% clearly exhibited that the response of modified electrode is stable because of the high adhesion of GNC layer on the paper substrate and the high stability of cDNA-Au@CD bioconjugates. The spike-and-recovery studies showed the acceptable recoveries for the sputum samples (>95%).
ABSTRACT
Zoonotic infections belong to multiple infectious diseases transferred from animals to humans. Now, the treatment and diagnosis of zoonotic infections are perplexing due to genetic mutations, target site modifications, and multi-drug resistance. Despite their benefits, most diagnostic molecular techniques have certain limits in terms of repeatability and sensitivity, mainly due to the heterogeneity among the diverse family of zoonotic pathogens. Therefore, developing more efficient and cost-effective theranostics tools is the need of the hour to address these concerns. For this purpose, nanotechnology has revolutionized medicine with versatile potential capabilities for diagnosing and treating zoonosis via the targeted and controlled delivery of antimicrobial drugs via binding to the overexpressed infectious macrophages. Massive advancements have been made in fabricating novel nano-based formulations to control zoonosis based on the use of poly(ethylenimine)-conjugated nanomicelles, mannosylated thiolated chitosan (MTC)-coated PM-loaded PLGA NPs, mannose linked thiolated nanocarriers, adjuvanted pDNA hydrogel, arginine-based nanocarriers, quantum dots to treat and diagnose a wide range of zoonotic diseases, including zoonotic influenza, salmonellosis, leishmaniasis, rabies, brucellosis, Lyme Disease, tuberculosis, and other infections caused by West Nile Virus, emerging coronaviruses (SARS, MERS, COVID-19), in a preferentially targeted way. Recently developed anti-pathogen loaded-nanoformulations with enhanced cellular uptake, biocompatibility, and hemocompatibility have shown the ability to cross biological barriers when orally administrated. Therefore, this article reviewed the latest milestones and future growth areas in the field of efficient theranostics platforms to manage zoonotic infections.