Browsing by Author "Debabrata Mishra"

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CISS-Based Label-Free Novel Electrochemical Impedimetric Detection of UVC-Induced DNA Damage
(American Chemical Society, 2022) Neeraj Bangruwa; Manish Srivastava; Debabrata Mishra
In this work, we demonstrate chiral-induced spin selectivity (CISS)-based label-free electrochemical impedimetric detection of radiation-induced DNA damage using the electrons' spin as a novel tool of sensing. For this, self-assembled monolayers (SAMs) of short ds-DNA (of length 7.14 nm) are prepared on arrays of multilayer thin film devices comprising a gold overlay (500 μm diameter with 10 nm thickness) on a nickel thin film (100 nm) fabricated by the physical vapor deposition technique. Subsequently, the SAMs of ds-DNA are exposed to ultraviolet C (UVC) radiation for a prolonged period of 8 h to induce structural perturbations in DNA. The susceptibility of DNA to radiation-induced damage was probed by recording the spin-dependent electrochemical impedimetric spectra, wherein a continuous sinusoidal wave of the amplitude of 10 mV was superimposed on DC bias in the frequency range of 100-105 Hz, with simultaneous spin injection through the attached DNA. The inherent correlation between the charge-transfer resistance (Rct) and the spin selectivity of electrons through DNA was taken into account for the detection of DNA damage for the first time with a limit of detection achieved up to 10 picomolar concentrations of DNA. As the spin-polarized electrons directly probe the structural symmetry, it is robust against perturbation from electronic signals usually found in conventional electrochemical biosensors. © 2016 American Chemical Society.
Efficient energy storage performance of in situ grown Co3V2O8-RGO composite nanostructure for high performance asymmetric Co3V2O8-RGO//RGO supercapacitors and consequence of magnetic field induced enhanced capacity
(Elsevier Ltd, 2021) Pooja Devi; Manish Srivastava; Nam Hoon Kim; Joong Hee Lee; Debabrata Mishra
In this work, cobalt vanadate/reduced graphene oxide (Co3V2O8/RGO) composite nanostructure has been synthesized via in-situ reduction of graphene oxide (GO) in the presence of cobalt chloride and sodium metavanadate through hydrothermal following post calcinations treatment. Characterizations through various techniques have been performed to probe the physicochemical properties of Co3V2O8/RGO, RGO and Co3V2O8 nanostructures. Our Results show that because of the synergistic effect, Co3V2O8/RGO composite nanostructure exhibits superior electrochemical properties as compared to bare RGO and Co3V2O8. At a current density of 0.5 A/g the specific capacity has been recorded to be 118.82, ∼179, and ∼241.67 Cg-1 in case of Co3V2O8, RGO and Co3V2O8/RGO nanostructures, respectively. Moreover, Co3V2O8/RGO composite nanostructure (positive electrode) and RGO (negative electrode) have been employed to prepare the asymmetric supercapacitor, exhibited high specific capacity (127.62Cg-1), energy density (28.36 Whkg−1), and power density (400 Wkg-1) at a current density 0.5 A/g. This asymmetric supercapacitor shows excellent capacity retention (∼91.64%) and columbic efficiency (∼98.61%) measured at a current density of 5 A/g after 10,000 charge/discharge cycles. More importantly, a dramatic increase ∼170% (344 Cg-1) and ∼67% (185 Cg-1) in the specific capacity have been recorded at a current density of 0.5 A/g and 1.0 A/g, respectively when asymmetric supercapacitor device is subjected to an external magnetic field of strength of 0.5 T. Additionally, under the applied magnetic field, capacity retention ∼97.75% and columbic efficiency ∼98.84% has been recorded at a current density of 5 A/g after 10,000 cycles. © 2021 Elsevier Ltd
Light-Amplified CISS-Based Hybrid QD-DNA Impedimetric Device for DNA Hybridization Detection
(American Chemical Society, 2023) Prashant K. Bhartiya; None Suryansh; Neeraj Bangruwa; Manish Srivastava; Debabrata Mishra
We design and build a novel light-amplified electrochemical impedimetric device based on the CISS effect to detect DNA hybridization using a hybrid quantum dot (QD)-DNA monolayer on a ferromagnetic (FM) Ni/Au thin film for the first time. Using spin as a detection tool, the current research considers the chiral-induced spin selectivity (CISS) phenomenon. After injecting a spin current into the QD-DNA system with opposite polarities (up and down), the impedimetric device revealed a large differential change in the charge-transfer resistance (ΔRct) of ∼100 ohms for both spins. Nearly, a threefold increase in the ΔRct value to ∼270 ohms is observed when light with a wavelength of 532 nm is illuminated on the sample, owing to the amplified CISS effect. The yield of spin polarization as extracted from the Nyquist plot increases by a factor of more than 2 when exposed to light, going from 6% in the dark to 13% in the light. The impact of light on the CISS effect was further corroborated by the observation of the spin-dependent asymmetric quenching of photoluminescence (PL) in the same hybrid system. These observations are absent in the case of a noncomplementary QD-DNA system due to the absence of a helical structure in DNA. Based on this, we develop a spin-based DNA hybridization sensor and achieve a limit of detection of 10 fM. These findings open a practical path for the development of spin-based next-generation impedimetric DNA sensors and point-of-care devices. © 2023 American Chemical Society