Challenges in Biomaterials Science for Electrochemical Biosensing and Bioenergy

Interest in developing and applying emerging biomaterials to sensing and energy devices' frameworks has dramatically climbed in recent years. The world has been recently threatened by the COVID-19 pandemic, generating a sprint for reliable manufacturing and analysis, low-cost detection methods. The challenge is implied in the elaboration of innovative materials and the design of biointerfaces to thrive in the sensing objectives. Concomitantly, the global search for economic growth and recovery is rebounding on energy demand, surpassing growth in energy generation from renewable sources. Therefore, efforts are being focused on the conception and application of biomaterials for the eco-friendly generation, storage, and conversion of energy. Here, we offer some highlights of the rational design of biomaterials and challenges to be overcome in the near future for the commercial consolidation of biodevices in these two segments.

Label-free electrochemical aptasensor for the detection of SARS-CoV-2 spike protein based on carbon cloth sputtered gold nanoparticles.

The proliferation and transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), or the (COVID-19) disease, has become a threat to worldwide biosecurity. Therefore, early diagnosis of COVID-19 is crucial to combat the ongoing infection spread. In this study we propose a flexible aptamer-based electrochemical sensor for the rapid, label-free detection of SARS-CoV-2 spike protein (SP). A platform made of a porous and flexible carbon cloth, coated with gold nanoparticles, to increase the conductivity and electrochemical performance of the material, was assembled with a thiol functionalized DNA aptamer via S-Au bonds, for the selective recognition of the SARS-CoV-2 SP. The various steps for the sensor preparation were followed by using scanning electron microscopy, cyclic voltammetry and differential pulse voltammetry (DPV). The proposed platform displayed good mechanical stability, revealing negligible changes on voltammetric responses to bending at various angles. Quantification of SARS-CoV-2 SP was performed by DPV and chronopotentiometry (CP), exploiting the changes of the electrical signals due the [Fe(CN)6]3-/4- redox probe, when SARS-CoV-2 SP binds to the aptamer immobilized on the electrode surface. Current density, in DPV, and square root of the transition time, in CP, varied linearly with the log[ SARS-CoV-2 SP], providing lower limits of detection (LOD) of 0.11 ng/mL and 37.8 ng/mL, respectively. The sensor displayed good selectivity, repeatability, and was tested in diluted human saliva, spiked with different SARS-CoV-2 SP concentrations, providing LODs of 0.167 ng/mL and 46.2 ng/mL for DPV and CP, respectively.