ABSTRACT
This work focuses on the synthesis of Bentonite supported nano zero valent bimetallic nanoparticles (B/nZVCu-M NPs) to be utilized for fast and highly sensitive, reversible, fluorescent determination of dopamine (DA) in the presence of dopamine, other biomolecules and ions. The X-ray Photoelectron Spectroscopy(XPS), Powder X-Ray Diffraction(PXRD) and Scanning Electron Microscopy(SEM) revealed the formation of nanoparticles with size ranging from 15 to 20 nm. The composition was revealed by Fourier Transform Infrared(FTIR) Spectoscopy and Energy Dispersive X-Ray (EDX) Analysis. The Limits of Detection(LOD) were noted to be 5.57nM and 6.07nM. The binding of DA is noted to be reversible with respect to EDTA2-. Furthermore, the developed sensor exhibited good repeatability, satisfactory long-term stability, and was successfully used for the selective detection of dopamine sample with desired recoveries or reversibilities. The main aim of our work is to selectively detect dopamine in presence of its major interferents and biomolecules that are normally present/ co-exist with dopamine in biological systems.
ABSTRACT
In this work, graphene oxide (GO) has been prepared from used dry cells using modified Hummer's method and encapsulated with montmorillonite clay. To enhance its electrical property, the GO-MMT composite has been functionalised with Basic Red 9 dye. The sensor was characterized by various spectroscopic techniques like FT-IR spectroscopy, PXRD, SEM analysis, etc. Basic Red 9 dye functionalised GO-MMT composite has been employed for fluorescent and electrochemical detection of Ce3+ ion. The fluorescent turn-on sensing is sensitive, reversible and free from interference from other metal ions. The detection of Ce3+ ion by the sensor was also conducted in bovine serum albumin (BSA) medium. Pt electrode modified with the hybrid sensor produces excellent electrochemical change in presence of Ce3+ ion through cyclic voltammetry and square wave voltammetry technique. The limit of detection (LOD) from fluorescence spectroscopy, cyclic voltammetry and square wave voltammetry were calculated to be 0.6556 × 10- 9 M, 1.232 × 10- 9 M and 1.923 × 10- 9 M respectively.
ABSTRACT
The dye Rosaniline hydrochloride (RANH) has been successfully incorporated in MCM-48 (designated as RANH@MCM-48) and characterized by various spectroscopic methods including FT-IR, SEM, EDX and N2 adsorption-desorption isotherm. RANH@MCM-48 in aqueous medium acts as fluorescence "on" sensor for neurotransmitter dopamine (DA) in presence of its main biological interfering agent ascorbic acid or vitamin c (AA) along with Glucose, Cholesterol and Uric acid (UA). The limits of detection (LOD) were found to be 65 nM and 51 nM respectively in absence and in presence of AA. The interaction of DA to RANH@MCM-48 is found to be reversible with respect to EDTA2-. The fluorescence intensity vs. pH plot shows a narrow fluorescence window of 7.2 to 8.8. RANH@MCM-48 has been successfully applied for DA detection in artificial cerebrospinal fluid (ACF) and bovine serum albumin (BSA) with LOD values 27 nM and 22.5 nM respectively. Platinum disc electrode has been modified with RANH@MCM-48 which showed distinct oxidation peaks with a separation of 0.188 V in cyclic voltammetry (CV). The LOD for DA in presence of AA determined from oxidation current is 77.5 nM. The voltammetric detection of DA is found to be free from common interfering species Na+, K+, Ca2+, Fe2+, UA, Cholesterol and Glucose. RANH@MCM-48 has been found to be a very effective fluorescence and voltammetric sensor for DA with very low LOD.