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El Sharif HF, Dennison SR, Tully M, Crossley S, Mwangi W, Bailey D, Graham SP, Reddy SM. Evaluation of electropolymerized molecularly imprinted polymers (E-MIPs) on disposable electrodes for detection of SARS-CoV-2 in saliva. Anal Chim Acta 2022; 1206:339777. [PMID: 35473858 PMCID: PMC8974637 DOI: 10.1016/j.aca.2022.339777] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/18/2022] [Accepted: 03/25/2022] [Indexed: 02/07/2023]
Abstract
We investigate electropolymerized molecularly imprinted polymers (E-MIPs) for the selective recognition of SARS-CoV-2 whole virus. E-MIPs imprinted with SARS-CoV-2 pseudoparticles (pps) were electrochemically deposited onto screen printed electrodes by reductive electropolymerization, using the water-soluble N-hydroxmethylacrylamide (NHMA) as functional monomer and crosslinked with N,N'-methylenebisacrylamide (MBAm). E-MIPs for SARS-CoV-2 showed selectivity for template SARS-CoV-2 pps, with an imprinting factor of 3:1, and specificity (significance = 0.06) when cross-reacted with other respiratory viruses. E-MIPs detected the presence of SARS-CoV-2 pps in <10 min with a limit of detection of 4.9 log10 pfu/mL, suggesting their suitability for detection of SARS-CoV-2 with minimal sample preparation. Using electrochemical impedance spectroscopy (EIS) and principal component analysis (PCA), the capture of SARS-CoV-2 from real patient saliva samples was also evaluated. Fifteen confirmed COVID-19 positive and nine COVID-19 negative saliva samples were compared against the established loop-mediated isothermal nucleic acid amplification (LAMP) technique used by the UK National Health Service. EIS data demonstrated a PCA discrimination between positive and negative LAMP samples. A threshold real impedance signal (ZRe) ≫ 4000 Ω and a corresponding charge transfer resistance (RCT) ≫ 6000 Ω was indicative of absence of virus (COVID-19 negative) in agreement with values obtained for our control non-imprinted polymer control. A ZRe at or below a threshold value of 600 Ω with a corresponding RCT of <1200 Ω was indicative of a COVID-19 positive sample. The presence of virus was confirmed by treatment of E-MIPs with a SARS-CoV-2 specific monoclonal antibody.
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Affiliation(s)
- H F El Sharif
- Department of Chemistry, UCLan Centre for Smart Materials, School of Natural Sciences, University of Central Lancashire, Preston, PR1 2HE, United Kingdom
| | - S R Dennison
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston, PR1 2HE, United Kingdom
| | - M Tully
- The Pirbright Institute, Pirbright, Woking, Surrey, GU24 0NF, United Kingdom
| | - S Crossley
- The Pirbright Institute, Pirbright, Woking, Surrey, GU24 0NF, United Kingdom
| | - W Mwangi
- The Pirbright Institute, Pirbright, Woking, Surrey, GU24 0NF, United Kingdom
| | - D Bailey
- The Pirbright Institute, Pirbright, Woking, Surrey, GU24 0NF, United Kingdom
| | - S P Graham
- The Pirbright Institute, Pirbright, Woking, Surrey, GU24 0NF, United Kingdom
| | - S M Reddy
- Department of Chemistry, UCLan Centre for Smart Materials, School of Natural Sciences, University of Central Lancashire, Preston, PR1 2HE, United Kingdom.
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