tetano
Editor, Senior Moderator
Proc Natl Acad Sci U S A
. 2022 Jul 12;119(28):e2206521119.
doi: 10.1073/pnas.2206521119. Epub 2022 Jun 28.
Rapid self-test of unprocessed viruses of SARS-CoV-2 and its variants in saliva by portable wireless graphene biosensor
Deependra Kumar Ban[SUP] 1 [/SUP], Tyler Bodily[SUP] 2 [/SUP], Abhijith G Karkisaval[SUP] 1 [/SUP], Yongliang Dong[SUP] 1 [/SUP], Shreyam Natani[SUP] 1 [/SUP], Anirudh Ramanathan[SUP] 2 [/SUP], Armando Ramil[SUP] 2 [/SUP], Sunil Srivastava[SUP] 3 [/SUP], Prab Bandaru[SUP] 1 4 [/SUP], Gennadi Glinsky[SUP] 5 [/SUP], Ratnesh Lal[SUP] 1 2 4 [/SUP]
Affiliations
Abstract
We have developed a DNA aptamer-conjugated graphene field-effect transistor (GFET) biosensor platform to detect receptor-binding domain (RBD), nucleocapsid (N), and spike (S) proteins, as well as viral particles of original Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) coronavirus and its variants in saliva samples. The GFET biosensor is a label-free, rapid (≤20 min), ultrasensitive handheld wireless readout device. The limit of detection (LoD) and the limit of quantitation (LoQ) of the sensor are 1.28 and 3.89 plaque-forming units (PFU)/mL for S protein and 1.45 and 4.39 PFU/mL for N protein, respectively. Cognate spike proteins of major variants of concern (N501Y, D614G, Y453F, Omicron-B1.1.529) showed sensor response ≥40 mV from the control (aptamer alone) for fM to nM concentration range. The sensor response was significantly lower for viral particles and cognate proteins of Middle East Respiratory Syndrome (MERS) compared to SARS-CoV-2, indicating the specificity of the diagnostic platform for SARS-CoV-2 vs. MERS viral proteins. During the early phase of the pandemic, the GFET sensor response agreed with RT-PCR data for oral human samples, as determined by the negative percent agreement (NPA) and positive percent agreement (PPA). During the recent Delta/Omicron wave, the GFET sensor also reliably distinguished positive and negative clinical saliva samples. Although the sensitivity is lower during the later pandemic phase, the GFET-defined positivity rate is in statistically close alignment with the epidemiological population-scale data. Thus, the aptamer-based GFET biosensor has a high level of precision in clinically and epidemiologically significant SARS-CoV-2 variant detection. This universal pathogen-sensing platform is amenable for a broad range of public health applications and real-time environmental monitoring.
Keywords: COVID-19; SARS-CoV-2; aptamer; biosensor; graphene.
. 2022 Jul 12;119(28):e2206521119.
doi: 10.1073/pnas.2206521119. Epub 2022 Jun 28.
Rapid self-test of unprocessed viruses of SARS-CoV-2 and its variants in saliva by portable wireless graphene biosensor
Deependra Kumar Ban[SUP] 1 [/SUP], Tyler Bodily[SUP] 2 [/SUP], Abhijith G Karkisaval[SUP] 1 [/SUP], Yongliang Dong[SUP] 1 [/SUP], Shreyam Natani[SUP] 1 [/SUP], Anirudh Ramanathan[SUP] 2 [/SUP], Armando Ramil[SUP] 2 [/SUP], Sunil Srivastava[SUP] 3 [/SUP], Prab Bandaru[SUP] 1 4 [/SUP], Gennadi Glinsky[SUP] 5 [/SUP], Ratnesh Lal[SUP] 1 2 4 [/SUP]
Affiliations
- PMID: 35763566
- DOI: 10.1073/pnas.2206521119
Abstract
We have developed a DNA aptamer-conjugated graphene field-effect transistor (GFET) biosensor platform to detect receptor-binding domain (RBD), nucleocapsid (N), and spike (S) proteins, as well as viral particles of original Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) coronavirus and its variants in saliva samples. The GFET biosensor is a label-free, rapid (≤20 min), ultrasensitive handheld wireless readout device. The limit of detection (LoD) and the limit of quantitation (LoQ) of the sensor are 1.28 and 3.89 plaque-forming units (PFU)/mL for S protein and 1.45 and 4.39 PFU/mL for N protein, respectively. Cognate spike proteins of major variants of concern (N501Y, D614G, Y453F, Omicron-B1.1.529) showed sensor response ≥40 mV from the control (aptamer alone) for fM to nM concentration range. The sensor response was significantly lower for viral particles and cognate proteins of Middle East Respiratory Syndrome (MERS) compared to SARS-CoV-2, indicating the specificity of the diagnostic platform for SARS-CoV-2 vs. MERS viral proteins. During the early phase of the pandemic, the GFET sensor response agreed with RT-PCR data for oral human samples, as determined by the negative percent agreement (NPA) and positive percent agreement (PPA). During the recent Delta/Omicron wave, the GFET sensor also reliably distinguished positive and negative clinical saliva samples. Although the sensitivity is lower during the later pandemic phase, the GFET-defined positivity rate is in statistically close alignment with the epidemiological population-scale data. Thus, the aptamer-based GFET biosensor has a high level of precision in clinically and epidemiologically significant SARS-CoV-2 variant detection. This universal pathogen-sensing platform is amenable for a broad range of public health applications and real-time environmental monitoring.
Keywords: COVID-19; SARS-CoV-2; aptamer; biosensor; graphene.