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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.

Ascorbic acid (AA) is an essential vitamin for human health. Therefore, fast and cost-effective detecting of AA is essential, whether in human or food samples. The purpose of this paper is to develop an electrochemical nanosensor for AA detection.

The proposed nanosensor was developed by printing carbon nanoparticles ink and silver nanoparticles ink on a polydimethylsiloxane (PDMS) substrate. The surface of the PDMS substrate was first treated by corona plasma. Then, the nanomaterials printer was used to deposit both inks on the substrate. The working electrode surface was modified by drop-casting of carbon nanotubes. Morphological evaluation was applied using scanning electron microscopy and cyclic voltammetry. Also, a potentiostat was used to detect AA by differential pulse voltammetry.

It has been shown that the developed nanosensor linearly worked at a range of (0–5 mM), with a limit of detection lower than 0.8 mM and a relative standard deviation of 6.6%.

The developed nanosensor is characterized by a simple and cost-effective sensing tool for AA. In particular, the nanomaterials enhanced the nanosensor’s sensitivity due to the high catalytic activity.

The purpose of this paper is to report on the development of a simple electrochemical nanobiosensor for early detection of pancreatic cancer. The nanobiosensor uses the newly emerged stable micro ribonucleic acid (miR-21) as a cancer-associated biomarker for diagnosis, prognosis or therapy response.

The biosensing practice consists of two main steps: capturing probe immobilization on a working electrode modified with multi-walled carbon nanotubes and gold nanoparticles (MWCNTs-AuNPs) and then sensing the miR-21 interaction electrochemically. Two electrochemical techniques, atomic force microscopy and Fourier-transform infrared spectroscopy, were applied for characterizations.

The nanobiosensor sensitivity exhibited satisfying results to miR-21 and demonstrated a wide dynamic range with a detection limit of just about 3.68 femtomolar using the source measure unit (SMU).

Researchers commonly use potentiostats to perform the differential pulse voltammetry (DPV) measurements for the electrochemical biosensing applications. In this study, the SMU was used to perform the DPV to detect the biomarker miR-21 using the MWCNTs-AuNPs screen-printed electrode as the electrochemical system.

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.