A-411 Rapid, Instrument-Free Detection of Cardiac Troponins: A Novel Colorimetric Assay for Acute Myocardial Infarction Diagnosis

Background Acute Myocardial Infarction (AMI) requires rapid and accurate diagnosis to enable timely intervention and improve outcomes. Current AMI diagnostics rely on lab-based troponin tests, which can take over an hour, or point-of-care devices requiring costly instrumentation, delaying critical decisions. Chemeleon’s Binding-Induced Nanostructured Dynamic Surface (BINDS) Assay is an instrument-free, rapid colorimetric diagnostic that detects cardiac troponins in under two minutes with lab-quality accuracy. By eliminating delays and reducing reliance on laboratory infrastructure, the BINDS Assay has the potential to improve triage, accelerate treatment, and reduce emergency department overcrowding. Methods Semi-quantitative instrument-free BINDS chips were produced from a standard semiconductor microfabrication process followed by a surface conjugation chemistry to immobilize molecular receptors (aptamers) onto the nanoengineered BINDS surface. Using predefined engineered micro-nanosurfaces with precise control of geometrical dimensions and surface chemistry treatment, we designed 4 different cut-off values for cardiac troponin I (cTnI) biomarker detection spanning from negative healthy groups to high-risk groups. We evaluated the preclinical performance of our BINDS assay by spiking different concentrations of cTnI recombinant proteins in whole blood samples from healthy donors, and a color change visible to the naked eye on the BINDS surface indicated the presence of cTnI biomarkers above the designed cut-off concentrations. The sample preparation (including the blood collection, dilution, and filtration) took under 2 minutes, while the readout of a visible color change was nearly instantaneous within 10 seconds. Analytical sensitivity, specificity, accuracy, and precision were calculated based on N=146 samples. Within-laboratory precision was assessed for all 4 cut-offs following the 20-day, two-runs-per-day design described in CLSI’s EP05 protocol with 5 trials for each of the cut-offs demonstrating the accuracy goal. Results A total of 146 samples (19 control samples and 127 positive samples) were evaluated to determine 4 different cut-offs, sensitivity, specificity, and accuracy. Based on the performance, the mean cut-off values were confirmed, as predicted, to be 15 ng/L for the 1st Bin, 25 ng/L for the 2nd Bin, 75 ng/L for the 3rd Bin, and 390 ng/L for the 4th Bin with the within-laboratory precision less than 10% CV (coefficient of variation). We further demonstrated that using the current specifications, the dynamic range of our semi-quantitative assay spanned from 1 ng/L to 4000 ng/L with a limit of detection (LoD) of 1 ng/L and a limit of Quantitation (LoQ) of 5ng/L. Moreover, the multi-range semi-quantitative BINDS assay presents a sensitivity of 99.2%, specificity of 90.5%, and accuracy of 97.9%. Conclusion The novel BINDS assay demonstrated excellent performance in quantifying differently designed cut-off values for cTnI levels ranging from healthy to high-risk groups with sufficient precision, sensitivity, specificity, and diagnostic accuracy to expedite pre-hospital identification of AMI patients presenting to the urgent care, ER, and during EMT transit.