A Label-Free and Antibody-Free Molecularly Imprinted Polymer-Based Impedimetric Sensor for NSCLC-Cells-Derived Exosomes Detection.

In this study, a label-free and antibody-free impedimetric biosensor based on molecularly imprinting technology for exosomes derived from non-small-cell lung cancer (NSCLC) cells was established. Involved preparation parameters were systematically investigated. In this design, with template exosomes anchored on a glassy carbon electrode (GCE) by decorated cholesterol molecules, the subsequent electro-polymerization of APBA and elution procedure afforded a selective adsorption membrane for template A549 exosomes. The adsorption of exosomes caused a rise in the impedance of the sensor, so the concentration of template exosomes can be quantified by monitoring the impedance of GCEs. Each procedure in the establishment of the sensor was monitored with a corresponding method. Methodological verification showed great sensitivity and selectivity of this method with an LOD = 2.03 × 103 and an LOQ = 4.10 × 104 particles/mL. By introducing normal cells and other cancer cells derived exosomes as interference, high selectivity was proved. Accuracy and precision were measured, with an obtained average recovery ratio of 100.76% and a resulting RSD of 1.86%. Additionally, the sensors' performance was retained at 4 °C for a week or after undergoing elution and re-adsorption cycles seven times. In summary, the sensor is competitive for clinical translational application and improving the prognosis and survival for NSCLC patients.

A molecularly imprinted electrochemical sensor based on surface imprinted polymerization and boric acid affinity for selective and sensitive detection of P-glycoproteins.

In this study, a molecular imprinted electrochemical sensor based on surface imprinting and boric acid affinity was prepared for the selective and sensitive detection of P-glycoprotein (P-gp) under physiological conditions. Several polymerization parameters were systematically investigated. Four electrochemical methods were used to characterize the sensors. It was proved that the glassy carbon electrode (GCE) was well modified by molecularly imprinted polymers (MIPs), and the electrochemical detection results were consistent with the theory. Methodological verification also showed that there were different linear relationships in the range of 1.0E-10-1.0E-1 µg/mL and 0.5-10 µg/mL with LOD = 2.233E-11 µg/mL and LOQ = 7.444E-11 µg/mL. The excellent selectivity and specificity of the sensor were demonstrated and the sensor could be stored in 1X PBS (0.01 M) at 4 °C for one week. Repeatability and intermediate precision were measured, and the RSD remained below 5%. In addition, the sensor could be reused up to three times without affecting the results of the measurements. The results of application showed that the sensor had a more accurate response value in 1% of plasma matrix. Compared with the detection results of ELISA kit method, the sensor had the advantages of wider detection range, shorter detection time, higher accuracy, simple operation and low cost, which indicated that the sensor had a certain practicability and clinical translational application capability. This study also provided a new idea and method for the detection of other high molecular weight biomarkers in complex biological samples.