Designing and optimization of an electrochemical substitute for the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay.

For the first time ever, this paper reports the development of an easily operated and cost-effective electrochemical assay to be used as an appropriate substitute for the MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cell viability assay. The proposed assay is based on the electrochemical reaction of Saccharomyces cerevisiae (S. cerevisiae) with toxic materials, and it overcomes most of the limitations of MTT such as evaporation of volatile solvents, cytotoxic effects of MTT reagents, high cost, and sensitivity to light. The novel electrochemical assay can be used to detect diazinon in the range of 10-6 g mL-1 to 10-2 g mL-1 with the detection limit of 1.5 × 10-7 g mL-1.

A distinguished cancer-screening package containing a DNA sensor and an aptasensor for early and certain detection of acute lymphoblastic leukemia.

A disposable package of biosensors was developed along with the corresponding guidelines for early detection of the acute lymphoblastic leukemia cancer. This proposed cancer-screening package included a DNA sensor and an aptasensor as two main types of biosensors. The biosensors were used simultaneously. This combination of sensors can detect not only the presence of mutant genes but also the biomarkers of cancer. At current work, the combination of sensors were used to detect the presence of BCR-ABL1 as a mutant gene and CEA as a biomarkers of cancer, such a capability makes the package liable for early and certain detection of acute lymphoblastic leukemia. To construct both the DNA sensor and the aptasensor, a nanocomposite consisting of electrosynthesis carbon quantum dots and biosynthesized gold nanoparticles was applied. The construction of these biosensors was characterized using four different electrochemical methods including DPV (Differential Pulse Voltammetry), EIS (Electrochemical Impedance Spectroscopy), CV (Cyclic Voltammetry) and chronoamperometry. The peak current of a catechol solution that was used as an electroactive probe on the biosensor was linearly related to the logarithm of the concentrations of the target DNA and the target antigen in the range of 10 pM to 100 µM and 1 pg mL-1 to 0.001 g mL-1 with the detection limits of 1.5 pM and 0.26 pg mL-1 respectively, which are quite good results.

A new composite consisting of electrosynthesized conducting polymers, graphene sheets and biosynthesized gold nanoparticles for biosensing acute lymphoblastic leukemia.

In this work we report the synthesis of a stable composite with excellent electrical properties, on the surface of a biosensor. Conductive polymers offer both high electrical conductivity and mechanical strength. Many reports have focused on synthesizing conductive polymers with the aid of high-cost enzymes. In the current work we introduce a novel electrochemical, one-step, facile and cost effective procedure for synthesizing poly (catechol), without using expensive enzymes. The poly (catechol) conductivity was enhanced by modification with graphene sheets and biosynthesized gold nanoparticles. Four different robust methods, DPV, EIS, CV and chronoamperometry, were used to monitor the biosensor modifications. The peak currents of the catechol (an electroactive probe) were linearly related to the logarithm of the concentrations of target DNA in the range 100.0 µM to 10.0 pM, with a detection limit of 1.0 pM for the DNA strand. The current work investigates a new, stable composite consisting of conductive polymers and nanoparticles, which was applied to the detection of acute lymphoblastic leukemia.