M. F. Hossain

Plain to point network reduced graphene oxide-activated carbon composites decorated with platinum nanoparticles for urine glucose detection.

In this study, a hydrothermal technique was applied to synthesize glucose-treated reduced graphene oxide-activated carbon (GRGO/AC) composites. Platinum nanoparticles (PtNP) were electrochemically deposited on the modified GRGO/AC surface, and chitosan-glucose oxidase (Chit-GOx) composites and nafion were integrated onto the modified surface of the working electrode to prepare a highly sensitive glucose sensor. The fabricated biosensor exhibited a good amperometric response to glucose in the detection range from 0.002 mM to 10 mM, with a sensitivity of 61.06 μA/mMcm2, a short response time (4 s) and a low detection limit of 2 μM (signal to noise ratio is 3). The glucose sensor exhibited a negligible response to interference and good stability. In addition, the glucose levels in human urine were tested in order to conduct a practical assessment of the proposed sensor, and the results indicate that the sensor had superior urine glucose recognition. These results thus demonstrate that the noble nano-structured electrode with a high surface area and electrocatalytic activity offers great promise for use in urine glucose sensing applications.

Trimetallic Pd@Au@Pt nanocomposites platform on -COOH terminated reduced graphene oxide for highly sensitive CEA and PSA biomarkers detection

In this paper, a trimetallic Pd@Au@Pt nanocomposites platform on -COOH terminated reduced graphene oxide (COOH-rGO) was newly developed for sensing carcinoembryonic antigen (CEA) and prostate specific antigen (PSA) biomarkers. Trimetallic electro-catalytic surfaces were prepared by the electrodeposition of noble metals (Pd@Au@Pt) nanoparticles on COOH- rGO. After EDC/NHS treatment, the anti-CEA and anti-PSA were immobilized separately on two different platforms. Under optimized conditions, the platforms were analyzed by cyclic voltammetry and differential pulse voltammetry (DPV). The platform shows good electro catalytic activity, high sensitivity, and acceptable stability for sensing CEA and PSA biomarkers. For CEA, we obtained sensitivity of 0.099 ± 0.007µAng-1ml, wide linear range from 12pgml-1 to 85ngml-1 and a limit of detection (LOD) of 8pgml-1, while for PSA sensitivity is 0.267 ± 0.02µAng -1 ml, wide linear range from 3pgml-1 to 60ngml-1 and LOD of 2pgml-1. The validation of the platform was observed through standard addition method. Thus, the sensing platform could be used for the point of care detection of CEA and PSA.

Palladium nanoparticles on electrochemically reduced chemically modified graphene oxide for non-enzymatic bimolecular sensing

This paper reports on the design, fabrication, and characterization of palladium nanoparticles (PdNPs) on electrochemically reduced chemically modified graphene oxide (ERCGO) modified gold substrate for enzyme-free bimolecular detection. The ERCGO-modified electrode was prepared electrochemically, which is a fast and controllable process due to the high cathodic reduction of oxygen functional groups of chemically modified graphene oxide on the surface of a gold substrate electrode in sodium hydroxide (NaOH) solution. Then, PdNPs were deposited electrochemically, which were dispersed homogeneously on the surface of ERCGO. The fabricated hybrid electrode exhibited good performance, along with low working potential, high sensitivity, low detection limit, and long-term stability, which are attributed to the high surface area of ERCGO that enabled the deposition of PdNPs. This electrode offers great promise for a new class of nanostructured electrodes, for non-enzymatic biosensor applications.

Novel enzymatic glucose biosensor based on distributed electrodes covered with a solvothermal synthesized graphene material and platinum nanoparticles

The progress of nanotechnology has encouraged scientists to continuously pursue new electrode materials for forming improved electrochemical platforms for sensing. In this study, an environmentally friendly reducing agent and optimum time were utilized to synthesize solvothermal-assisted reduced graphene oxide (TRGO) that can be easily exfoliated in a coating solution and substituted on the microelectrode surface. Series connected distributed sensing electrodes were fabricated and patterned with TRGO decorated platinum nanoparticles (PtNPs), chitosan–enzyme composites, and Nafion, which were integrated onto the modified surface for effective glucose detection. The developed biosensor demonstrated good current response to glucose with a high sensitivity, short response time, and low detection limit of 41.18 μA mM−1 cm−2, 5 s, and 0.0019 mM, respectively. The interference phenomena, reproducibility and the durability of the biosensor, were also examined. In addition, glucose levels in human urine were tested for a practical assessment of the proposed biosensor, and the results indicate that the sensor had superior urine glucose recognition. These results reveal that this noble nanostructured electrode with high surface area and electrocatalytic activity offers great promise for use in enzymatic biosensor applications.

A highly performed nonenzymatic glucose sensor using surfactant template assisted platinum nanoparticles

In this work, we have successfully developed an enzyme free glucose sensor with highly performed electrodes, which was decorated with surfactant assisted platinum nanoparticles (PtNPs) on rectangular shaped thin Au film electrode. The PtNPs have been used for their outstanding catalytic activity for the redox reaction of H2O2. Diblock copolymer surfactant template was used to deposit platinum nanoparticles on the working and counter electrodes, simultaneously. Optimal potential was investigated and applied for the uniform distribution of PtNPs. The fabricated biosensor showed good electrocatalytic performance in terms of high sensitivity of 0.32 μA/mM, fast response of 5 s, and wide linear range from 0.0625 to 22 mM.