Electrochemical aptasensing of human cardiac troponin I based on an array of gold nanodumbbells-Applied to early detection of myocardial infarction

•A new nanoaptasensor was introduced for detection of troponin I.•This aptasensor could detect troponin I in a wide linear range a low limit of detection.•The aptasensor was applied in the analysis of 89 real samples.

Recently, convergence of nanotechnology, medicine, biology and chemistry has provided novel solutions for efficient diagnosis systems for disease markers. A detection method of troponin I (TnI), as the gold standard of acute myocardial infarction biomarker, was investigated and a novel aptasensor was presented for this biomarker. An array of gold nanodumbbells was firstly synthesized using putrescine as the shape directing agent at a surface. It was then applied as a transducer for the immobilization of a 76-mer TnI aptamer to fabricate a simple electrochemical TnI aptasensor. Using the aptasensor, TnI was detected in a linear range of 0.05-500 ng mL−1 with a limit of detection of 8.0 pg mL−1. The aptasensor showed a diagnostic sensitivity of 100% and a diagnostic specificity of 85% when challenged with blood serum samples of 89 individuals.