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This paper aims to report a prototype of a reliable method for rapid, sensitive bacterial detection by using a low-cost zinc oxide nanorods (ZnONRs)-based electrochemical sensor.

The ZnONRs have been grown on the surface of a disposable, miniaturized working electrode (WE) using the low-temperature hydrothermal technique. Scanning electron microscopy and energy dispersion spectroscopy have been performed to characterize the distribution as well as the chemical composition of the ZnONRs on the surface, respectively. Moreover, the cyclic voltammetry test has been implemented to assess the effect of the ZnONRs on the signal conductivity between −1 V and 1 V with a scan rate of 0.01 V/s. Likewise, the effect of using different bacterial concentrations in phosphate-buffered saline has been investigated.

The morphological characterization has shown a highly distributed ZnONR on the WE with uneven alignment. Also, the achieved response time was about 12 minutes and the lower limit of detection was approximately 103 CFU abbreviation for Colony Forming Unit/mL.

This paper illustrates an outcome of an experimental work on a ZnONRs-based electrochemical biosensor for direct detection of bacteria.

This paper aims to report on the development of a novel electrochemical amperometric immunosensor to diagnose early hepatocellular carcinoma (HCC) by detecting the Midkine (MDK) biomarker.

Anti-Midkine antibodies were immobilized covalently through carbodiimides chemistry on carbon screen-printed electrodes modified with carboxylated multi-walled carbon nanotubes. The development process was characterized using cyclic voltammetry, electrochemical impedimetric spectroscopy, Fourier transform infrared spectroscopy and atomic force microscopy. Differential pulse voltammetry was used to investigate the immunosensor performance in detecting MDK antigen within the concentration range of 1 pg/ml to 100 ng/ml.

MDK immunosensor exhibited high sensitivity and linearity with a detection limit of 0.8 pg/ml and a correlation coefficient of 0.99. The biosensor also demonstrated high selectivity, stability and reproducibility.

The developed MDK immunosensor could be a promising tool to diagnose HCC and reduce the number of related deaths.