In the present study, nanoceria-decorated MWCNTs (CeNPs@MWCNTs) were synthesized using a simple and inexpensive process. Molnupiravir (MPV) has gained considerable attention in recent years due to the infection of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Since some people infected with COVID-19 experience fever and headaches, paracetamol (PCM) has been prescribed to relieve these symptoms. Therefore, there is an urgent need to monitor and detect these drugs simultaneously in pharmaceutical and biological samples. In this regard, we developed a novel sensor based on nanoceria-loaded MWCNTs (CeNPs@MWCNTs) for simultaneous monitoring of MPV and PCM. The incorporation of CeNPs@MWCNTs electrocatalyst into a glassy carbon microsphere fluorolube oil paste electrode (GCMFE) creates more active sites, which increase the surface area, electrocatalytic 

A new fluorescence sensing approach has been proposed for the precise determination of the anti-cancer drug oxaliplatin (Oxal-Pt). This method entails synthesizing blue-emitting copper nanoclusters (CuNCs) functionalized with bovine serum albumin (BSA) as the stabilizing agent. Upon excitation at 360 nm, the resultant probe exhibits emission at 460 nm. Notably, the fluorescence response of BSA@CuNCs substantially increases upon incubation with Oxal-Pt due to multiple binding interactions between the drug and the fluorescent probe. These interactions involve hydrogen bonding, hydrophobic interaction, and the high affinity between the SH groups (cysteine residues of BSA) and platinum (in Oxal-Pt). Consequently, this interaction induces aggregation-induced emission enhancement (AIEE) of BSA@CuNCs. The probe demonstrates a broad response range from 0.08 to 140.0 μM, along with a low detection 

Nanostructures that can undergo redox reactions have significant potential for electrochemical analysis. They can act as signal amplifiers to determine concentrations of targets in biological samples. In this work, a rational combination of electroactive copper‐based metal‐organic frameworks (Cu‐MOFs) and ferrocene carboxylic acid (Fc) was designed for ratiometric electrochemical detection of creatinine. The synthesized Fc@Cu‐MOFs exhibited two redox signals from the Cu²⁺/Cu⁺ and Fe³⁺/Fe²⁺ systems in the skeleton of Cu‐MOFs and Fc, respectively. In the presence of chloride (Cl⁻), the oxidation current of Cu⁺ increased due to formation of solid‐state cuprous chloride (CuCl). Adding strong Cu⁺ chelators, e. g. creatinine, coordinated with Cu⁺ and caused the current output of solid‐state CuCl to decrease significantly. The anodic current of Fc did not appreciably change, serving as an internal reference signal. The ratiometric responses (I_Cu(I)/I_Fc) changed with increasing concentrations of creatinine from 0.017–130 μM with a detection limit (S/N=3) of 0.005 μM. The main advantages of Fc@Cu‐MOFs are the low LOD, high selectivity, and reliability, making it a suitable platform for determining creatinine in human serum and urine samples. The as‐fabricated sensor is a reliable approach for determining (bio) molecules that can form stable complexes with Cu⁺ ions.

In this research paper, a novel “signal on–off” ratiometric-based electrochemical platform was developed for the sensitive and selective detection of captopril. Ratiometric responses were achieved by fabricating molecularly imprinted polymers (MIPs) on the surface of a graphite electrode (GE) decorated with nitrogen (N) and sulfur (S) co-doped porous carbon and silver nanoparticles (Ag). The MIP layer was formed via electropolymerization of copper coordinated with pyrrole-3-carboxylic acid (functional monomer). Silver nanoparticles (Ag) were incorporated to enhance conductivity and surface area and to serve as an internal reference output. Upon the addition of captopril, there was a decrease in the anodic oxidation current of Ag+ at around 0.067 V, coupled with an increase in the oxidation current at 0.54 V (Ag–captopril complex). Under optimized conditions, the electrochemical responses (IAg–captopril/IAg 

In the current study, the potential interaction mechanisms between capmatinib (CAP), a selective tyrosine kinase inhibitor, and calf thymus double-stranded DNA (ds-DNA) were evaluated. In this research, we construct an amplified electrochemical platform based on a disposable pencil graphite electrode (PGE) modified with nanostructured CeO2 decorated carbon nanofiber ceramic film (CeNPs@CNF-CF) for monitoring CAP–dsDNA interaction at physiological pH. The morphology and structure of the obtained CeNPs@CNF nanocomposite were characterized. The CeNPs@CNF-CF/PGE was characterized by scanning electron microscopy (SEM). The CAP–dsDNA interaction was examined using cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. Voltammetric experiments were conducted using CeNPs@CNF-CF/PGE. The interaction of CAP with dsDNA was investigated after applying …

In the current study, the first voltammetric method is constructed for the ultrasensitive quantification of capmatinib (CMT), a targeted therapy drug falls within the category of tyrosine kinase inhibitors (TKIs), using a modified carbon nanofibers paste electrode (CNFs-PE). Nanogold-loaded porous acetylene black (Au@PAB) as a conductive hybrid nanofiller incorporating carbon nanofiber networks (CNFs) was synthesized. The surface morphology of the synthesized Au@PAB and the ternary nanocomposite Au@PAB/CNFs was elucidated using various analytical techniques. The results show Au@PAB hybrid nanofiller incorporated CNFs has a critical property that increases electrocatalytic performance. The impact of scan rate, pH, and supporting electrolyte on the electrocatalytic response of CMT was explored on the Au@PAB/CNFs-PE nanosensor. Under optimum adsorptive stripping square-wave voltammetric …

In this study, we have constructed a novel voltammetric sensor based on montmorillonite clay (MMT) incorporated with CeO₂ nanoparticles using a composite graphite paste electrode as a cross linker (MMT-CeO₂NPs/GPG-PE) for the trace determination of tadalafil (TAD) drug. The characterization of CeO₂ nanoparticles has been conducted using various analytical techniques, including X-ray diffraction, transmission electron microscopy, and high-resolution transmission electron microscopy. The morphology of the composite of CPG and MMT-CeO₂NPs/CPG was elucidated through scanning electron microscopy (SEM). The newly developed sensor (MMT-CeO₂NPs/CPG-PE) exhibited remarkable efficiency towards TAD oxidation using adsorptive stripping square-wave voltammetry (AdS-SWV) in Mcllvaine buffer solution (pH 8.0). A highly selective and sensitive method for TAD detection has been successfully …

A novel and sensitive fluorescence ratiometric method is developed for urea detection based  on the pH-sensitive response of two fluorescent carbon dot (CD) systems: R-CDs/methyl red (MR) and NIR-CDs/Cu²⁺. The sensing mechanism involves breaking down urea using the enzyme urease, releasing ammonia and increasing pH. At higher pH, the fluorescence of NIR-CDs is quenched due to the enhanced interaction with Cu²⁺, while the fluorescence of R-CDs is restored as the acidic MR converts to its basic form, removing the inner filter effect. The ratiometric signal (F₆₀₈/F₇₅₀) of the R-CDs/MR and NIR-CDs/Cu²⁺ intensities changed in response to the pH induced by urea hydrolysis, enabling selective and sensitive urea detection. Detailed spectroscopic and morphological investigations confirmed the fluorescence probe design and elucidated the sensing mechanism. The method exhibited excellent …

The monitoring of ziram levels is of vital importance due to its widespread application in agriculture and the possible risks it poses to human health and the ecosystem. This work proposes an innovative approach for the highly sensitive and selective sensing of ziram, a widely used dithiocarbamate fungicide, through the formation of copper dimethyldithiocarbamate Cu)DDC)₂ assisted dual quenching of red and blue emission carbon dots (R/NCDs and B/NSCDs). When ziram is added to a system containing copper-bound B/NSCDs and R/NCDs, the displacement of ziram zinc ions by copper ions leads to the formation of a yellow-colored Cu)DDC)₂ complex. This complex induces significant quenching of the fluorescence emissions from both types of carbon dots, consequently enhancing the sensitivity of the detection method. Comprehensive characterization of the R/NCDs and B/NSCDs was conducted using …