No abstract

Acute myocardial infarction (AMI) causes irreversible injury to cardiomyocytes in a short time and may result in various complications, severely threatening patient safety. Therefore, it is necessary to predict the possibility of AMI in the prophase. Prognostic detection of biomarkers that specifically reflect myocardial damage in a patient’s blood has become an essential mediating measure to prevent the serious occurrence of AMI. The present study is aimed at exploring a novel sensing system with high specificity and precision based on magnetic microspheres developed to detect cardiac troponin T (cTnT), which is the most specific diagnostic marker for AMI in cardiovascular diseases. Naive human cTnT protein in serum samples and antigens on functional magnetic microspheres will competitively bind with limited specific antibodies. After rapid removal of heterogeneous elements in the sera using a magnetic separator, fluorescein isothiocyanate-labeled immunoglobulin G is added to react with specific antibodies on the magnetic microspheres. Then, a flow cytometer is used to collect signals of different fluorescence intensities. The results show that the method is characterized by economy, high accuracy, and novelty. It can be used for the detection of cTnT in blood at 1.7–106.1 ng/mL, with a detection limit of 0.5 ng/mL. Thus, the proposed sensor improves the accuracy and efficiency of diagnosis before clinical deterioration of AMI.

Au nanoparticles (NPs) have been proven to be excellent glucose oxidase (GOx) mimics, which can catalyze the electrons transform pathway from glucose to oxygen. This study confirmed AuNPs can accelerate the reaction between [Ag(NH3)2]+ and glucose under alkaline conditions, which is also known as the Tollens′ reaction, and the possible mechanism was proposed. Here, [Ag(NH3)2]+ instead of O2 acted directedly as an electron acceptor during glucose oxidation catalyzed by AuNPs, accompanied by hydrogen transfer. The as‐synthesized Ag nanoparticles can also catalyze this process, similar to AuNPs, via a unique cascading catalysis mechanism in the Tollens′ reaction. A simple and heatless glucose colorimetric assay can be established based on the plasmonic band of AgNPs with a liner range of 0.6–22.2 μM, and the limit of detection is 0.32 μM.