Reduced Graphene OxideTEMPONanocellulose NanohybridBased Electrochemical Biosensor for the Determination of Mycobacterium tuberculosis A novel peptide nuclide acid (PNA) electrochemical biosensor based on reduced graphene oxide (NH2rGO)2,2,6,6tetramethylpiperidin1yl)oxyl nanocrystalline cellulose (TEMPONCC) for the detection of Mycobacterium tuberculosis (M. Tuberculosis) is described. In this study, the nanohybrid films NH2rGOTEMPONCC were immobilized onto screenprinted carbon electrode (SPE) via a simple dropcoating method. The electrochemical characterization of the designed electrode was investigated using cyclic voltammetry (CV) and impedance spectroscopy (EIS). Meanwhile, the sensitivity and selectivity of the designed biosensor against M. tuberculosis were measured by the differential pulse voltammetry (DPV). The response of the PNA probemodified (NH2rGO)TEMPONCC demonstrated that the fabricated biosensor was able to distinguish between complementary, noncomplementary, and onebase mismatch DNA sequences using methylene blue (MB) as the electrochemical indicator. The developed electrochemical biosensor exhibited a linear calibration curve in the concentration range of                               to                                  with the limit of detection of                                          .   The developed electrochemical biosensor has also been tested with a polymerase chain reaction (PCR) product of M. tuberculosis DNA which has shown successful results in distinguishing between negative and positive samples of M. tuberculosis.

Voltammetry at HexamethylPTerphenyl Poly(Benzimidazolium) (HMTPMBI)Coated Glassy Carbon Electrodes: Charge Transport Properties and Detection of Uric and Ascorbic Acid We describe the voltammetric behavior of an anionexchange membrane, hexamethylpterphenyl poly(benzimidazolium) (HMTPMBI). The anionexchange properties of HMTPMBI chemically modified electrodes were investigated using K4Fe(CN)6 and K2IrCl6 as redox probes. The permselectivity properties of HMTPMBI chemically modified electrodes were ascertained using tris(22xe2x80x99)bipyridylruthenium(II) chloride Ru(bpy)32. Cyclic voltammetry and chronoamperometry were utilized to extract parameters such as the concentration of the redox mediators inside the films and the apparent diffusion coefficients. We found the concentration of K4Fe(CN)6 and K2IrCl6 redox species within HMTPMBIcoated films to be on the order of 0.04xe2x80x930.1 molxc2xb7dmxe2x88x923, and values of Dapp ca. 10xe2x88x9210xe2x80x9310xe2x88x929 cm2xc2xb7sxe2x88x921. To evaluate the possibility of using such a polymer coating in electroanalysis, HMTPMBImodified electrodes were utilized for the voltammetric detection of uric acid in artificial urine, Surinexc2xae and ascorbic acid in Vitamin C samples. The results showed that HMTPMBIcoated electrodes can detect uric acid in Surinexc2xae with a limit of detection (LoD) of 7.7 xc2xb5M, sensitivity of 0.14 xc2xb5Axc2xb7xc2xb5Mxe2x88x921xc2xb7cmxe2x88x922, and linear range between 5 xcexbcM and 200 xcexbcM, whereas for Vitamin C tablets, the LoD is 41.4 xc2xb5M, the sensitivity is 0.08 xc2xb5Axc2xb7xc2xb5Mxe2x88x921xc2xb7cmxe2x88x922, and the linear range is between 25 xcexbcM and 450 xcexbcM.