Highly Sensitive and Quick Detection of Acute Myocardial Infarction Biomarkers Using In 2 O 3 Nanoribbon Biosensors Fabricated Using Shadow Masks.

We demonstrate a scalable and facile lithography-free method for fabricating highly uniform and sensitive In ₂ O ₃ nanoribbon biosensor arrays. Fabrication with shadow masks as the patterning method instead of conventional lithography provides low-cost, time-efficient, and high-throughput In ₂ O ₃ nanoribbon biosensors without photoresist contamination. Combined with electronic enzyme-linked immunosorbent assay for signal amplification, the In ₂ O ₃ nanoribbon biosensor arrays are optimized for early, quick, and quantitative detection of cardiac biomarkers in diagnosis of acute myocardial infarction (AMI). Cardiac troponin I (cTnI), creatine kinase MB (CK-MB), and B-type natriuretic peptide (BNP) are commonly associated with heart attack and heart failure and have been selected as the target biomarkers here. Our approach can detect label-free biomarkers for concentrations down to 1 pg/mL (cTnI), 0.1 ng/mL (CK-MB), and 10 pg/mL (BNP), all of which are much lower than clinically relevant cutoff concentrations. The sample collection to result time is only 45 min, and we have further demonstrated the reusability of the sensors. With the demonstrated sensitivity, quick turnaround time, and reusability, the In ₂ O ₃ nanoribbon biosensors have shown great potential toward clinical tests for early and quick diagnosis of AMI.