Reagentless Quantum-Rate-Based Electrochemical Signal of Graphene for Detecting SARS-CoV-2 Infection Using Nasal Swab Specimens

Abstract

The quantum-rate model predicts a rate k as a frequency for transporting electrons within molecular structures, which is governed by the ratio between the quantum of conductance G and capacitance C q , such that k = G/C q . This frequency, as measured in a single-layer graphene appropriately modified with suitable biological receptors, can be applied as a transducer signal that ranges sensitivities within the attomole for biosensing applications.Here, we applied this label-free and reagentless biosensing transducer signal methodology for the qualitative diagnosis of COVID-19 infections, where this assay methodology was shown to be similar to the gold-standard real-time polymerase chain reaction. The quantum-rate strategy for the diagnosis of COVID-19 was performed by combining the response of the interface for detecting the S and N proteins of SARS-CoV-2 virus as accessed from nasopharyngeal/oropharyngeal patient samples with 80% of sensitivity and 77% of specificity. As a label-free and reagentless biosensing platform, the methodology is decidedly useful for point-of-care and internet-of-things biological assaying technologies, not only because of its real-time ability to measure infections but also because of the capability for miniaturization inherent in reagentless electrochemical methods. This approach effectively permits the rapid development of biological assays for surveillance and control of endemics and pandemics.

Quantum Rate Theory for Graphene

“…Ultimately, the theory allows us to conclude that an AC architecture for transistors must perform with much better efficiency (for the quantum transport of information and energy) than our traditional DC mode of using logical transistor operations. Apparently, nature has already accomplished this through the transport of electrons within electrochemical energy levels in complex biological structures, allowing us to predict an avenue of possibilities for using graphene in biological sensing application, for instance, see ref .…”

Applications of Graphene in Five Senses, Nervous System, and Artificial Muscles

“…Second, the nucleic acid biosensors are efficient for early diagnosis of genetic diseases, e.g., miRNA21 (breast cancer), as well as mass screening of coronavirus disease 2019. − Indeed, the DNA aptamer modified graphene transistor promotes the detection of viruses in several minutes for self-test at home . Recently, CRISPR technique was integrated with transistor platform for breaking the detection limit to attomole per liter level …”

The Emergence of Carbon Nanomaterials as Effective Nano-Avenues to Fight against COVID-19

“…The response of the biosensor was assessed by real-time monitoring of the resistance change caused by antigen-antibody interaction with a LOD value of 10 fM. For the purpose of detecting SARS-CoV-2 infection using nasal swab specimens, Garrote et al [ 45 ] created an AC GFET that acted as a reagent-less quantum-rate-based electrochemical biosensing platform. According to the quantum-rate model, the frequency of electron transport inside molecular structures, as measured in graphene that has biological receptors, may be employed as a transducer signal at the interface with attomole-level sensitivity for biosensing.…”