Rapid Detection of Troponin I from Serum using Microwave-Accelerated Metal-Enhanced Fluorescence

Abstract

In a clinical setting, immunoassays for the quantification of cardiac markers are usually run in serum and can take > 15 minutes to process per step, per marker; resulting in a long patient screening process. Some commercially available tests for cardiac markers offer results from whole blood in approximately 15 minutes. However, these systems measure one sample at a time and have high initial and maintenance / supply costs. In this regard, the development of new ultra-fast (< 30 seconds) and sensitive immunoassays for cardiac markers, that can predict an AMI accurately, earlier and more economically, will significantly benefit human health. Our Laboratory recently reported the application of a platform technology, namely “Microwave-Accelerated Metal Enhanced Fluorescence (MAMEF)” to a model protein assay in HTS well plates, where low concentrations of a target protein were detected in less than 30 seconds.1Here we present our findings on the rapid detection of Troponin I from samples prepared in buffer and serum on HTS well plates using the MAMEF platform technology. In this regard, HTS wells were firstly modified with silver colloids and cardiac marker specific capture antibody. Subsequently, the Troponin I immunoassay was undertaken by the incubation of Troponin I and the detection antibody under microwave irradiation for 30 seconds for each step. A lower detection of < 1 ng/mL for Troponin I in buffer and serum was recorded. In addition, the detection of Troponin I from I-T-C complex in buffer and serum was also achieved with a lower detection limit < 1 ng/mL using MAMEF. Our findings demonstrate that cardiac markers can be determined in < 30 seconds at clinically relevant levels.1. Aslan, K., Holley, P. & Geddes, C.D. Journal of Immunological Methods 312, 137 (2006).