Improving Functional Behavior of MCM‐41 by Encapsulating MnO₂ Nanorods towards Simultaneous Determination of Purine Bases in DNA Samples

Abstract

MnO2 nanorods incorporated MCM‐41 nanocomposite (MnO2@MCM‐41) is synthesized and employed as an electrode modifier for individual as well as simultaneous detection of purine bases, guanine (GU) and adenine (AD). For this purpose MnO2 nanorods are encapsulated within MCM‐41 by simple one pot synthetic approach. FT‐IR, UV‐vis absorption spectroscopy, scanning electron microscopy, energy dispersive X‐ray spectroscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy and electrochemical methods are employed to characterize the nanocomposite and other materials. The electrochemical attributes of glassy carbon electrode (GCE) modified with the MnO2@MCM‐41 (represented as GCE/MnO2@MCM‐41) towards the determination of GU and AD is studied in detail. Upon incorporation of MnO2 nanorods on MCM‐41, noticeable upsurge in anodic peak current with a decline in peak potential is observed for both GU and AD oxidations in cyclic voltammetry studies. Individual as well as simultaneous determination of GU and AD are performed using differential pulse voltammetry (DPV) technique which offered a linear range of 100 nM to 100 μM for GU and AD with respective limit of detections, 44 and 66 nM. The practical applicability of the GCE/MnO2@MCM‐41 for real world samples analysis is satisfactorily demonstrated with certain DNA samples by DPV.

Facile Synthesis of Sulfur-Doped Mesoporous Carbon Nitride Supported Defect-Rich Cobalt Sulfide for Electrocatalytic Water Oxidation

“…The low-angle powder XRD pattern of O-Co 3 S 4 @S-MCN (Figure S1a in the Supporting Information) displays a diffraction peak at around 2.1° (2θ) and a hump at around 4.5° (2θ), which are attributed to the replica of MCM-41. This indicates the presence of mesopores in the O-Co 3 S 4 @S-MCN material . The peak at 2.1° (2θ) can be ascribed to the (001) plane and the hump at around 4.5° (2θ) is attributed to the overlapped peaks of the (110) and (200) set of planes.…”

“…The pore size and shape of the adsorption/desorption isotherm (type IV) confirm the mesoporous nature of the material . The lower specific surface area of O-Co 3 S 4 @S-MCN in contrast to that of MCM-41 is attributed to cobalt sulfide formation on the pore surfaces.…”

“…This indicates the presence of mesopores in the O-Co 3 S 4 @S-MCN material. 25 The peak at 2.1°(2θ) can be ascribed to the (001) plane and the hump at around 4.5°(2θ) is attributed to the overlapped peaks of the (110) and ( 200) set of planes. The presence of two well-separated peaks in the range of 4.0−5.0°generally represents the formation of regular 2D hexagonal structures.…”

“…The mesoporous silica material MCM-41 was synthesized using a previously reported method . Further, it was used as a hard template for the synthesis of the composite O-Co 3 S 4 @S-MCN (sulfur-doped mesoporous carbon nitride supported defect-rich cobalt sulfide).…”

“…The mesoporous silica material MCM-41 was synthesized using a previously reported method. 25 Further, it was used as a hard template for the synthesis of the composite O-Co 3 S 4 @S-MCN (sulfur-doped mesoporous carbon nitride supported defect-rich cobalt sulfide). In a typical synthesis, MCM-41 (0.2 g) in 10 mL of triply distilled water was mixed with 1.0 g of thiourea and 0.15 g of cobalt(II) chloride.…”