A green, simple, and cost effective electrochemical method to synthesize pure graphene oxide (GO) and graphene nanosheets (GNs) using pencil in ionic liquid medium is reported. The morphology and microstructure of prepared GNs and GO are examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X‐ray diffraction (XRD), and Raman spectroscopy; the experiments confirm the formation of high quality graphene. The synthesized GO is used for the real‐time and label‐free surface plasmon resonance (SPR) sensing of the biological warfare agent Salmonella typhi.

A disposable amperometric immunosensor was developed for the detection of Plasmodium falciparum histidine-rich protein 2 (PfHRP-2) in the sera of humans with P. falciparum malaria. For this purpose, disposable screen-printed electrodes (SPEs) were modified with multiwall carbon nanotubes (MWCNTs) and Au nanoparticles. The electrodes were characterized by cyclic voltammetry, scanning electron microscopy, and Raman spectroscopy. In order to study the immunosensing performances of modified electrodes, a rabbit antiPfHRP-2 antibody (as the capturing antibody) was first immobilized on an electrode. Further, the electrode was exposed to a mouse anti-PfHRP-2 antibody from a serum sample (as the revealing antibody), followed by a rabbit anti-mouse immunoglobulin G-alkaline phosphatase conjugate.

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SummaryTwo different kinds of CuO nanoparticles (NPs) namely CuO nanorods (PS2) and multi-armed nanoparticles (P5) were synthesized by wet and electrochemical routes, respectively. Their structure, morphology, size and compositions were characterized by SEM, EDX and XRD. The NPs demonstrated strong bactericidal potential against Bacillus anthracis cells and endospores. PS2 killed 92.17% of 4.5 × 104 CFU/mL B. anthracis cells within 1 h at a dose of 1 mg/mL. Whereas P5 showed a higher efficacy by killing 99.92% of 7 × 105 CFU/mL B. anthracis cells within 30 min at a dose of 0.5 mg/mL and 99.6% of 1.25 × 104 CFU/mL B. anthracis cells within 5 min at a dose of 2 mg/mL. More than 99% of spores were killed within 8 h with 2 mg/mL PS2 in LB media.

We report herein the amperometric immunosensor for antibodies to Plasmodium falciparum histidine rich protein-2 (PfHRP-2). Screen-printed electrodes (SPEs) were modified with alumina sol-gel (Al(2)O(3) sol-gel) derived film and gold nanoparticles i.e. AuNPs/Al(2)O(3)sol-gel/SPE. A thin film was formed by dripping Al(2)O(3) sol on SPE followed by electrochemical deposition of gold nanoparticles (AuNPs). The modified SPEs were characterized by scanning electron microscopy/energy dispersive X-ray analysis (SEM-EDAX), Raman spectra and voltammetric experiments. Antibodies in rabbit serum sample were allowed to react with the PfHRP-2 protein that was immobilized on the modified SPE to form antigen-antibody immune complex (PfHRP-2/anti-PfHRP-2). The bound antibodies were quantified by alkaline phosphatase (AP) enzyme labeled secondary antibodies (anti-rabbit immunoglobulins-AP conjugate). Enzymatic substrate, 1-naphthyl phosphate was converted to 1-naphthol by AP and an electroactive product was quantified using amperometry. The performances of the developed immunosensor and Dot-ELISA were tested against different dilutions of hyper immune serum (rabbit anti-PfHRP-2). Dot ELISA and the developed immunosensor (AuNPs/Al(2)O(3)sol-gel/SPE) results for the hyper immune serum containing anti-PfHRP-2 were distinctly positive when diluted upto 8 times (1 : 12800 dilution) and 11 times (1 : 102400 dilution), respectively. The developed immunosensor was applied for antibodies to PfHRP-2 in human clinical samples.

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