biostudies-literatureTayyab MDARPA Cooperative AgreementNational Science Foundation20119https://www.ebi.ac.uk/biostudies/studies/S-EPMC9684124biostudies-literatureUnknown12(1)Proteins are useful biomarkers for a wide range of applications such as cancer detection, discovery of vaccines, and determining exposure to viruses and pathogens. Here, we present a low-noise front-end analog circuit interface towards development of a portable readout system for the label-free sensing of proteins using Nanowell array impedance sensing with a form factor of approximately 35cm². The electronic interface consists of a low-noise lock-in amplifier enabling reliable detection of changes in impedance as low as 0.1% and thus detection of proteins down to the picoMolar level. The sensitivity of our system is comparable to that of a commercial bench-top impedance spectroscope when using the same sensors. The aim of this work is to demonstrate the potential of using impedance sensing as a portable, low-cost, and reliable method of detecting proteins, thus inching us closer to a Point-of-Care (POC) personalized health monitoring system. We have demonstrated the utility of our system to detect antibodies at various concentrations and protein (45 pM IL-6) in PBS, however, our system has the capability to be used for assaying various biomarkers including proteins, cytokines, virus molecules and antibodies in a portable setting.Scientific reportsA portable analog front-end system for label-free sensing of proteins using nanowell array impedance sensors.PMC9684124IDBR Award No. 1846740,CAREER Award No. 1556253, and ECCS-CCSS Award No. 1711165.HR0011-16-2-0026Raji HSami MAMahmoodi SRJavanmard MTayyab MLin ZMeng ZXie PfalseA portable analog front-end system for label-free sensing of proteins using nanowell array impedance sensors.Proteins are useful biomarkers for a wide range of applications such as cancer detection, discovery of vaccines, and determining exposure to viruses and pathogens. Here, we present a low-noise front-end analog circuit interface towards development of a portable readout system for the label-free sensing of proteins using Nanowell array impedance sensing with a form factor of approximately 35cm². The electronic interface consists of a low-noise lock-in amplifier enabling reliable detection of changes in impedance as low as 0.1% and thus detection of proteins down to the picoMolar level. The sensitivity of our system is comparable to that of a commercial bench-top impedance spectroscope when using the same sensors. The aim of this work is to demonstrate the potential of using impedance sensing as a portable, low-cost, and reliable method of detecting proteins, thus inching us closer to a Point-of-Care (POC) personalized health monitoring system. We have demonstrated the utility of our system to detect antibodies at various concentrations and protein (45 pM IL-6) in PBS, however, our system has the capability to be used for assaying various biomarkers including proteins, cytokines, virus molecules and antibodies in a portable setting.2022-01-01T00:00:00Z2022 Nov2025-04-27T03:03:28.989Z2025-04-06T18:39:58.76ZS-EPMC96841243641885210.1038/s41598-022-23286-7