Nano optical and electrochemical sensors and biosensors for detection of narrow therapeutic index drugs

For the first time, a comprehensive review is presented on the quantitative determination of narrow therapeutic index drugs (NTIDs) by nano optical and electrochemical sensors and biosensors. NTIDs have a narrow index between their effective doses and those at which they produce adverse toxic effects. Therefore, accurate determination of these drugs is very important for clinicians to provide a clear judgment about drug therapy for patients. Routine analytical techniques have limitations such as being expensive, laborious, and time-consuming, and need a skilled user and therefore  the nano/(bio)sensing technology leads to high interest.

Poly (Adenine) Modified Graphene-Based Voltammetric Sensor for the Electrochemical Determination of Catechol, Hydroquinone and Resorcinol

Objective:

This paper presents the application of Poly (Adenine) Modified Graphene Paste Electrode (PAMGPE) for the analysis of Catechol (CC) with Resorcinol (RC) and Hydroquinone (HQ) by a voltammetric technique.

Methods:

Electropolymerization technique was utilized for the modification of the sensor surface. The electrode surface was characterized by Field Emission Scanning Electron Microscopy (FE-SEM). Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) were used to study the redox behavior of CC, RC and HQ.

Results:

Oxidation peak current of CC increased linearly with the concentration of CC in the range from 2×10-6- 8×10-6 M and 1×10-5-1.5 ×10-4 M with a detection limit of 2.4×10-7 M. The practical application of the developed sensor was verified as exact for the determination of CC in water sample.

Conclusion:

The stability, repeatability, and reproducibility of the developed electrode were studied and established good characteristics. Furthermore, the PAMGPE was examined for the simultaneous determination of CC, RC and HQ.

Electrochemical Polymerised Graphene Paste Electrode and Application to Catechol Sensing

Objective:

To build up an advantageous strategy for sensitive determination of catechol (CC), a poly (proline) modified graphene paste electrode (PPMGPE) was fabricated and used as a voltammetric sensor for the determination of CC.

Methods:

The performance of the modified electrode was studied using cyclic voltammetric (CV) and differential pulse voltammetric method (DPV). The modified electrode was characterized by CV and DPV. The surface of the modified electrode was examined by FESEM. The electrochemical behavior of CC in phosphate buffer solution (pH 7.5) was inspected using bare graphene paste electrode (BGPE) and PPMGPE.

Results & Conclusion:

The PPMGPE shows a lower limit of detection, calculated to be 8.7×10–7mol L−1 (S/N=3). This modified electrode was applied successfully for the determination of CC in water samples without applying any sample pretreatment.