Two new MOFs based ECL aptasensors showed ultra-sensitivity towards the α-syn oligomer, an important biomarker for Parkinson's disease.

A simple, dual-modular aptasensor for accurate determination of cardiac troponin I (cTnI), a sensitive biomarker of acute myocardial infarction, is reported. It has the parallel output of electrochemiluminescence (ECL) and electrochemical impedance spectroscopy (EIS) based on target-gated transportation of signal probes (luminol/H2O2 or Fe­(CN)6 3–/4–). The sensing capacity is originated from the amino-functionalized mouth margin of the nanochannels in a vertically oriented mesoporous silica film, which was in situ-grown on indium tin oxide-coated glass. With the linkage of glutaraldehyde to couple the aptamer as a trapper, it brings in the high specific target-gated response toward cTnI as decreased ECL or increased EIS. The concentration of cTnI is measurable by the ECL response within a wide linear range from 0.05 pg mL–1 to 10 ng mL–1, as well as the EIS response for a linear range between 0.05 pg mL–1 and 1 ng mL–1. Significantly, the self-verification of these two data from ECL and EIS validated each other with a satisfactory linear correlation (R 2 = 0.999), thereby realizing the more reliable and accurate quantification to avoid false results. The designed strategy is an effective method for detection of cTnI, which is of great potential to apply in clinical detection.

The accurate assay of cardiac troponin I (cTnI) is very important for acute myocardial infarction (AMI), it also can be employed as an effective index for screening serious patients in COVID-19 pandemic before fatal heart injury to reduce the mortality. A ratiometric sensing strategy was proposed based on electrochemiluminescent (ECL) signal of doxorubicin (Dox)-luminol or the electrochemical (EC) signal of methylene blue (MB) vs. referable EC signal of Dox. The bio-recognitive Tro4-aptamer ensures the high specificity of the sensor by affinity binding to catch cTnI, and the tetrahedral DNA (TDs) on Au/Ti 3 C 2 -MXene built an excellent sensing matrix. An in situ hybrid chain reaction (HCR) amplification greatly improved the sensitivity. The ratiometric sensing responses ECL Dox-luminol / Current Dox or Current MB / Current Dox linearly regressed to cTnI concentration in the range of 0.1 fM-1 pM or 0.1 fM-500 fM with the limit of detection (LOD) as 0.04 fM or 0.1 fM, respectively. Served as the reference signal, Current Dox reflected the variation of sensor, it is very effective to ensure the accuracy of detection to obviate the false results. The proposed biosensors show good specificity, sensitivity, reproducibility and stability, have been applied to determine cTnI in real samples with satisfactory results. They are worth looking forward to be used for screening serious patient of COVID-19 to reduce the mortality, especially in mobile cabin hospital.

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