biostudies-literatureMalla PMinistry of Science and Technology, TaiwanChang Gung UniversityChang Gung Memorial Hospital, Linkou168https://www.ebi.ac.uk/biostudies/studies/S-EPMC8973645biostudies-literatureUnknown189(4)The rapid spread of the novel human coronavirus 2019 (COVID-19) and its morbidity have created an urgent need for rapid and sensitive diagnostics. The real-time polymerase chain reaction is the gold standard for detecting the coronavirus in various types of biological specimens. However, this technique is time consuming, labor intensive, and expensive. Screen-printed electrodes (SPEs) can be used as point-of-care devices because of their low cost, sensitivity, selectivity, and ability to be miniaturized. The ability to detect the spike protein of COVID-19 in serum, urine, and saliva was developed using SPE aided by magnetic beads (MBs) and a portable potentiostat. The antibody-peroxidase-loaded MBs were the captured and catalytic units for the electrochemical assays. The MBs enable simple washing and homogenous deposition on the working electrode using a magnet. The assembly of the immunological MBs and the electrochemical system increases the measuring sensitivity and speed. The physical and electrochemical properties of the layer-by-layer modified MBs were systematically characterized. The performance of these immunosensors was evaluated using spike protein in the range 3.12-200 ng mL^-1. We achieved a limit of detection of 0.20, 0.31, and 0.54 ng mL^-1 in human saliva, urine, and serum, respectively. A facile electrochemical method to detect COVID-19 spike protein was developed for quick point-of-care testing.Mikrochimica actaVoltammetric biosensor for coronavirus spike protein using magnetic bead and screen-printed electrode for point-of-care diagnostics.PMC8973645BMRP 758110-2221-E-182-0242H0073Liu CHWu WCSreearunothai PMalla PLiao HPfalseVoltammetric biosensor for coronavirus spike protein using magnetic bead and screen-printed electrode for point-of-care diagnostics.The rapid spread of the novel human coronavirus 2019 (COVID-19) and its morbidity have created an urgent need for rapid and sensitive diagnostics. The real-time polymerase chain reaction is the gold standard for detecting the coronavirus in various types of biological specimens. However, this technique is time consuming, labor intensive, and expensive. Screen-printed electrodes (SPEs) can be used as point-of-care devices because of their low cost, sensitivity, selectivity, and ability to be miniaturized. The ability to detect the spike protein of COVID-19 in serum, urine, and saliva was developed using SPE aided by magnetic beads (MBs) and a portable potentiostat. The antibody-peroxidase-loaded MBs were the captured and catalytic units for the electrochemical assays. The MBs enable simple washing and homogenous deposition on the working electrode using a magnet. The assembly of the immunological MBs and the electrochemical system increases the measuring sensitivity and speed. The physical and electrochemical properties of the layer-by-layer modified MBs were systematically characterized. The performance of these immunosensors was evaluated using spike protein in the range 3.12-200 ng mL^-1. We achieved a limit of detection of 0.20, 0.31, and 0.54 ng mL^-1 in human saliva, urine, and serum, respectively. A facile electrochemical method to detect COVID-19 spike protein was developed for quick point-of-care testing.2022-01-01T00:00:00Z2022 Apr2025-04-04T23:34:39.697Z2025-04-04T23:34:39.697ZS-EPMC89736453536275910.1007/s00604-022-05288-4