Beduk D.Ilton de Oliveira Filho J.Beduk T.Harmanci D.Zihnioglu F.Cicek C.Sertoz R.2023-01-122023-01-122022259013702590-1370https://doi.org/10.1016/j.biosx.2022.100105https://hdl.handle.net/11454/79531Point of care (PoC) devices are highly demanding to control current pandemic, originated from severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). Though nucleic acid-based methods such as RT-PCR are widely available, they require sample preparation and long processing time. PoC diagnostic devices provide relatively faster and stable results. However they require further investigation to provide high accuracy and be adaptable for the new variants. In this study, laser-scribed graphene (LSG) sensors are coupled with gold nanoparticles (AuNPs) as stable promising biosensing platforms. Angiotensin Converting Enzyme 2 (ACE2), an enzymatic receptor, is chosen to be the biorecognition unit due to its high binding affinity towards spike proteins as a key-lock model. The sensor was integrated to a homemade and portable potentistat device, wirelessly connected to a smartphone having a customized application for easy operation. LODs of 5.14 and 2.09 ng/mL was achieved for S1 and S2 protein in the linear range of 1.0–200 ng/mL, respectively. Clinical study has been conducted with nasopharyngeal swabs from 63 patients having alpha (B.1.1.7), beta (B.1.351), delta (B.1.617.2) variants, patients without mutation and negative patients. A machine learning model was developed with accuracy of 99.37% for the identification of the SARS-Cov-2 variants under 1 min. With the increasing need for rapid and improved disease diagnosis and monitoring, the PoC platform proved its potential for real time monitoring by providing accurate and fast variant identification without any expertise and pre sample preparation, which is exactly what societies need in this time of pandemic. © 2022en10.1016/j.biosx.2022.100105info:eu-repo/semantics/openAccessCOVID-19Laser-scribed grapheneMachine learningPoint-of-careSARS-CoV-2SensorBinding energyDiagnosisDiseasesGold nanoparticlesMachine learningPolymerase chain reactionProteinsSARSControl currentCOVID-19Laser-scribed grapheneLongest processing timePoint of carePoint of care diagnosticSample preparationSensorSevere acute respiratory syndrome coronavirusSevere acute respiratory syndrome coronavirus 2Grapheneangiotensin converting enzyme 2coronavirus spike glycoproteingold nanoparticleArticlebinding affinitycoronavirus disease 2019humanmachine learningmajor clinical studynasopharyngeal swabnonhumanpatient monitoringpoint of care testingSARS-Cov-2 variant 501Y.V1SARS-CoV-2 variant 501Y.V2SARS-CoV-2 variant VUI-21APR-01Severe acute respiratory syndrome coronavirus 2virus identificationvirus strainArticle102-s2.0-85122650697Q1