An extended-gate field-effect transistor (EG-FET) signal transducing combined with epitope molecular imprinting for selective chemosensing of chosen idiopathic pulmonary fibrosis (IPF) biomarkers

We propose a relatively rapid and straightforward procedure for the determination of chosen idiopathic pulmonary fibrosis (IPF) predictive protein biomarkers, vis., matrix metalloproteinase-1 (MMP-1) and surfactant-associated protein-A (SP-A), suitable for their determination in bodily fluids. IPF is a lethal lung disease, annually causing nearly as many deaths as breast cancer. Moreover, the coronavirus recently triggered acute exacerbation of patients suffering from IPF. Here, epitopes specific to the chosen IPF biomarkers were molecularly imprinted in a polymer as an alternative to imprinting fragile whole biomarkers' molecules. A thin molecularly imprinted polymer (MIP) film-based recognition units were integrated by electropolymerization with gates of extended-gate field-effect transistors (EG-FETs) to fabricate biomarker-selective chemical sensors suitable as point-of-care testing (POCT) diagnostic devices. Either AQDDIDGIQAI or FKGNKYWAVQGQNV single-epitope imprinting allowed determining the MMP-1 biomarker in the 10 to 250 nM linear dynamic concentration range with a LOD of 7.5 or 2 nM, respectively. Simultaneous imprinting of three MMP-1 epitopes, vis., MIAHDFPGIGHK, HGYPKDIYSS, and FKGNKYWAVQGQNV, decreased this LOD to 0.1 nM, allowing for determining this biomarker in serum. Moreover, by FSSNGQSIT or YSDGTPVNYTNWYR single-epitope imprinting, chemosensors for SP-A were fabricated to show the versatility of epitope imprinting. These chemosensors selectively determined the SP-A biomarker with the LOD of 1.9 or 2.9 nM, allowing its determination in bodily fluids.