Excellent Adsorption of Lead (II) and Chromium (VI) from Water Using Zwitterions (-NH3+ and -COO-) Functionalized Nano Lanthanum Oxide: Kinetic, Isotherm, Thermodynamic, and Surface Mechanism.

Zwitterion amino acid l-cysteine functionalized lanthanum oxide nanoparticles (l-Cyst-La2O3 NPs) have been synthesized for the first time with lanthanum acetate as the precursor, NH4OH as the base, and l-cysteine as the in situ functionalized mediator. The typical size of l-Cyst-La2O3 NPs was obtained in the range of 15-20 nm from the TEM technique. A cytotoxicity test of l-Cyst-La2O3 NPs was performed in Raw 264.7 cell lines, which were shown to be highly biocompatible. The point zero charge pH (pHPZC) of bare and l-Cyst functionalized La2O3 NPs was obtained at pH 6 and 2. The maximum uptake capacities of l-Cyst-La2O3 NPs at temperatures 25-45 °C were obtained as 137-282 mg/g for Pb2+ and 186-256 mg/g for Cr6+. All of these values are much higher than those reported in the literature with other nanomaterials. The presence of -SH, -NH2, and -COOH functional groups in zwitterion l-cysteine provides multiple binding sites leading to the high adsorption of Pb2+ and Cr6+. Five-cycle desorption studies were successfully performed to regenerate the spent l-Cyst-La2O3 NPs.

Electrochemically microplastic detection using chitosan-magnesium oxide nanosheet.

Microplastics, an invisible threat, are emerging as serious pollutants that continuously affect health by interrupting/contaminating the human cycle, mainly involving food, water, and air. Such serious scenarios raised the demand for developing efficient sensing systems to detect them at an early stage efficiently and selectively. In this direction, the proposed research reports an electrochemical hexamethylenetetramine (HMT) sensing utilizing a sensing platform fabricated using chitosan-magnesium oxide nanosheets (CHIT-MgO NS) nanocomposite. HMT is considered as a hazardous microplastic, which is used as an additive in plastic manufacturers and has been selected as a target analyte. To fabricate sensing electrodes, a facile co-precipitation technique was employed to synthesize MgO NS, which was further mixed with 1% CHIT solution to form a CHIT_MgO NS composite. Such prepared nanocomposite solution was then drop casted to an indium tin oxide (ITO) to fabricate CHIT_MgO NS/ITO sensing electrode to detect HMT electrochemically using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. To determine the limit of detection (LOD) and sensitivity, DPV was performed. The resulting calibrated curve for HMT, ranging from 0.5 µM to 4.0 µM, exhibited a sensitivity of 12.908 µA (µM)-1 cm-2 with a detection limit of 0.03 µM and a limit of quantitation (LOQ) of 0.10 µM. Further, the CHIT_MgO NS/ITO modified electrode was applied to analyze HMT in various real samples, including river water, drain water, packaged water, and tertiary processed food. The results demonstrated the method's high sensitivity and suggested its potential applications in the field of microplastic surveillance, with a focus on health management.

A novel method for enrichment of Morganella morganii in fecal samples using designed culture medium.

Morganella morganii is a gram negative, facultative anaerobic rod-shaped bacterium, commonly found in environment and in the intestine of human, mammals, and reptiles as a part of their gut microbiome. M. morganii can cause Gram-negative folliculitis, black nail infection, acute retiform purpura, fetal demise, and subdural empyema. The increasing frequency of M. morganii infections generate the need for efficient methods to enrich the presence of M. morganii in clinical samples to make its detection easier. Culturomics aims to grow and maximize the number of culturable bacteria. Different methods are followed to maximize the growth of minority population of bacteria by disrupting the growth of bacteria which are present in higher concentration. This article presents a method for selective enriching the M. morganii in human fecal samples. This method includes prior incubation of fecal microbiota in an anaerobic environment, adding supplement like fecal water to give dormant bacteria a break to become active to grow to threshold concentration, and an enrichment stage which provides the additional opportunity of growing to M. morganii on the selective medium. This method also provides an ingenuous way for augmenting the growth of fecal M. morganii species.

Graphene oxide-Mn3O4nanocomposites for advanced electrochemical biosensor for fumonisin B1 detection.

Occurrence of mycotoxins in food samples threat to its safety issue due to the presence of high toxicity and carcinogenic behavior, thus requiring highly sensitive and selective detection. Herein, the trimanganese tetraoxide (Mn3O4) nanoparticles in combination with graphene oxide (GO) nanocomposite were used to enhance the electrochemical performance for fabrication of electrochemical biosensor for fumonisin B1 (FB1) detection. The various characterization tools were used to validate the fabrication of GOMn3O4nanocomposites. To fabricate the electrochemical biosensor on an indium tin oxide (ITO) coated glass substrate, a thin film of GOMn3O4nanocomposite was prepared using electrophoretic deposition technique, and antibodies (ab-FB1) were immobilized onto the electrode for selective FB1 detection. The differential pulse voltammetry technique was used to observe the sensing performance. The non-binding sites of the ab-FB1 on the immunoelectrode were blocked with bovine serum albumin (BSA). The biosensor electrode was fabricated as BSA/ab-FB1/GOMn3O4/ITO for the detection of FB1. The sensitivity of the biosensor was obtained as 10.08µA ml ng-1cm-2in the detection range of 1 pg ml-1to 800 ng ml-1with a limit of detection of 0.195 pg ml-1. In addition, the recovery of BSA/ab-FB1/GOMn3O4/ITO immunoelectrodes was also performed on sweet corn samples and is calculated to be 98.91%.

Rapid and label-free detection of Aflatoxin-B1viamicrofluidic electrochemical biosensor based on manganese (III) oxide (Mn3O4) synthesized by co-precipitation route at room temperature.

Aflatoxin B1 (AFB1) is the most toxic mycotoxin, naturally occurring in food items, and it causes several types of lethal diseases. Therefore, a rapid and convenient detection method for AFB1 is the first step toward overcoming the effect of AFB1. The current work presents the development of an efficient microfluidic electrochemical-based biosensor using tri-manganese tetroxide nanoparticles (Mn3O4nps) for AFB1 detection. The Mn3O4nps were synthesized at room temperature through the co-precipitation route. Its phase purity, structural and morphological studies have been characterized through x-ray diffraction, Raman spectroscopy, energy-dispersive x-ray, Fourier transform infrared spectroscopy and transmission electron microscopy. The mask-less UV-lithography was carried out to fabricate the three-electrode chip and microfluidic channel of the microfluidic electrochemical biosensing system. The designed microfluidic immunosensor (BSA/Ab-AFB1/Mn3O4/ITO) was fabricated using the three-electrode chip, microfluidic channel in poly-dimethyl siloxane. The fabricated sensor exhibited the 3.4µA ml ng-1cm-2sensitivity and had the lowest lower detection limit of 0.295 pg ml-1with the detection range of 1 pg ml-1to 300 ng ml-1. Additionally, the spiked study was also performed with this immunoelectrode and a recovery rate was obtained of 108.2%.

Non-enzymatic and rapid detection of glucose on PVA-CuO thin film using ARDUINO UNO based capacitance measurement unit.

Glucose measurement is one of the essential health monitoring practices for maintaining blood sugar levels. Here, we have fabricated a highly specific capacitive nano-sensor for non-enzymatic glucose detection. Capacitance measurements were carried out on polyvinyl alcohol capped copper oxide (PVA-CuO) thin films on indium tin oxide (ITO) coated glass using ARDUINO UNO. The capacitance study shows a decrease in capacitance with an increase in glucose concentrations. The applicability in real samples was performed by studying the glucose in the presence of fetal bovine serum. Most commonly found interfering agents were used for interference studies, which confirmed the capacitive nano-sensor specificity. The system was further checked for repeatability up to six readings and reproducibility up to 5 chips. The shelf-life study showed stability for four weeks of a chip. These studies indicate that this capacitance-based measurement unit can be used for reliable, rapid, and non-enzymatic detection of glucose in real sample.

Evaluation of size, shape, and charge effect on the biological interaction and cellular uptake of cerium oxide nanostructures.

Cerium oxide (CeO2) at the nanoscale has prolifically attracted the immense interest of researchers due to its switchable oxidation states (Ce3+/Ce4+) that play a crucial role in many biological activities. The present work reports the evaluation of size, shape, and charge effect on the biological interaction with RAW 264.7 cells for three nanostructures of CeO2(CeO2NS) namely nanocubes (NCs), nanorods (NRs), and nanoparticles (NPs). These NS exhibits similar composition and have average diameter values in the order of NCs < NRs â‰… NPs. The values of zeta potential revealed the anionic nature of NS with surface charge in order of NCs < NPs < NRs. The cellular interaction of CeO2NS was analyzed for cytotoxicity, cellular uptake, and morphological studies. Quantitative determination of the uptake of CeO2NS exhibited concentration-dependent uptake in the order as NCs > NPs > NRs. The proposed possible mechanisms of cellular uptake revealed that different structures tended to use the various endocytosis pathways in different proportions.

Emerging role of trimethylamine-N-oxide (TMAO) in colorectal cancer.

Among gut microbiota-derived metabolites, trimethylamine-N-oxide (TMAO) is receiving increased attention due to its possible role in the carcinogenesis of colorectal cancer (CRC). In spite of numerous reports implicating TMAO with CRC, there is a lack of empirical mechanistic evidences to concretize the involvement of TMAO in the carcinogenesis of CRC. Possible mechanisms such as inflammation, oxidative stress, DNA damage, and protein misfolding by TMAO have been discussed in this review in the light of the latest advancements in the field. This review is an attempt to discuss the probable correlation between TMAO and CRC but this linkage can be concretized only once we get sufficient empirical evidences from the mechanistic studies. We believe, this review will augment the understanding of linking TMAO with CRC and will motivate researchers to move towards mechanistic study for reinforcing the idea of implicating TMAO with CRC causation. KEY POINTS: • TMAO is a gut bacterial metabolite which has been implicated in CRC in recent years. • The valid mechanistic approach of CRC causation by TMAO is unknown. • The article summarizes the possible mechanisms which need to be explored for validation.

Carbon cloth-based immunosensor for detection of 25-hydroxy vitamin D3.

Vitamin D (VD) deficiency is a global health concern due to its serious health impacts, and at present, the monitoring of VD status is expensive. Here, a novel immunosensor for sensitive and label-free detection of 25-hydroxy vitamin D3 (25VD3) is reported. Nanostructured cerium(IV) oxide (nCeO2) was anchored onto carbon cloth (CC) via electrophoretic deposition to fabricate a nanoplatform (nCeO2/CC). Subsequently, bioactive molecules (anti-25VD3 and BSA) were introduced to fabricate the nanobioplatform BSA/anti-25VD3/nCeO2/CC as an immunosensor. The analytical performance of the developed immunosensor was studied towards 25VD3 detection. The immunosensor provides a broad linear range of 1-200 ng mL-1, high sensitivity of 2.08 µA ng-1 mL cm-2, a detection limit of 4.63 ng mL-1, and a response time of 15 min, which is better than that of previous reports. The biosensor exhibited high selectivity, good reproducibility, and excellent stability for about 45 days. The potential application of the proposed immunosensor was observed for real serum samples towards 25VD3 detection that demonstrated a high correlation with the conventional enzyme-linked immunosorbent assay. Graphical abstract.

Studies on carbon-quantum-dot-embedded iron oxide nanoparticles and their electrochemical response.

A report on the synthesis of carbon-quantum-dot-embedded iron oxide nanoparticles (CQD@Fe3O4NPs) and their improved electrochemical studies is presented. Fe3O4NPs and CQD@Fe3O4NPs were synthesized by the wet-chemical co-precipitation method. X-ray diffraction measurements exhibited pure cubic phase with Fd3m space group in Fe3O4NPs and CQD@Fe3O4NPs. Fourier-transform infrared spectroscopy measurements confirmed the functionalization of Fe3O4NPs with CQDs. Dynamic light scattering measurements revealed a hydrodynamic radius of 520 nm and 319 nm for Fe3O4NPs and CQD@Fe3O4NPs, respectively. Moreover, zeta potential measurements showed positively charged Fe3O4NPs and negatively charged CQD@Fe3O4NPs. High-resolution transmission electron microscopy measurements showed nearly spherical structure with an average size of around 7 nm for Fe3O4 in both samples, whereas CQDs were nearly 2 nm in size in CQD@Fe3O4NPs. A biocompatibility study showed that CQD@Fe3O4NPs were more biocompatible than the bare Fe3O4NPs. CQD@Fe3O4NPs were then dispersed in chitosan (CHIT) solution, and drop-casted onto an indium tin oxide (ITO) glass substrate for further study. Atomic force microscopy results showed improved surface roughness of the CQD@Fe3O4-CHIT/ITO electrode, providing a better biosensing platform. The electrochemical response studies of CQD@Fe3O4-CHIT/ITO also showed enhanced electrochemical signal compared to Fe3O4-CHIT/ITO electrodes. Thus, a CQD@Fe3O4-CHIT/ITO electrode was used for the detection of vitamin D2 (10-100 ng ml-1) using a differential pulse voltammetry technique. The sensitivity and limit of detection were obtained as 0.069 µA ng-1 ml cm-2 and 2.46 ng ml-1, respectively.

Mesoporous polyaniline nanofiber decorated graphene micro-flowers for enzyme-less cholesterol biosensors.

In the present work, we have studied a nanocomposite of polyaniline nanofiber-graphene microflowers (PANInf-GMF), prepared by an in situ rapid mixing polymerization method. The structural and morphological studies of the nanocomposite (PANInf-GMF) were carried out by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FTIR) and Raman spectroscopy. The mesoporous, nanofibrous and microflower structures were observed by scanning electron microscopy. The functional groups and synergetic effects were observed by FTIR and micro-Raman measurements. The water wettability was carried out by a contact angle measurement technique and found to be super hydrophilic in nature towards water. This nanocomposite was deposited onto indium-tin-oxide coated glass substrate by a drop casting method and used for the detection of cholesterol using an electrochemical technique. The differential pulse voltammetry studies show the appreciable increase in the current with the addition of 1.93 to 464.04 mg dl(-1) cholesterol concentration. It is also found that the electrodes were highly selective towards cholesterol when compared to other biological interfering analytes, such as glucose, urea, citric acid, cysteine and ascorbic acid. The sensitivity of the sensor is estimated as 0.101 µA mg(-1) dl cm(-2) and the lower detection limit as 1.93 mg dl(-1). This work will throw light on the preparation of non-enzymatic biosensors based on PANInf-carbon nanostructure composites.

Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection.

We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe(3)O(4))) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe(3)O(4) and CA-Fe(3)O(4)/ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe(3)O(4), CA-Fe(3)O(4) nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe(3)O(4)) and 189.51 nm (CA-Fe(3)O(4)) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe(2)O(3)/ITO immunosensor exhibits a good detection range of 12.5-500 ng mL(-1) with a low detection limit of 0.32 ng mL(-1), sensitivity 0.03 Ω/ng ml(-1) cm(-2), and reproducibility more than 11 times.

4-Ethylphenyl Sulfate Detection by an Electrochemical Sensor Based on a MoS2 Nanosheet-Modified Molecularly Imprinted Biopolymer.

One of the gut-derived uremic toxins 4-ethylphenyl sulfate (4-EPS) exhibits significantly elevated plasma levels in chronic kidney diseases and autism, and its early quantification in bodily fluids is important. Therefore, the development of rapid and sensitive technologies for 4-EPS detection is of significant importance for clinical diagnosis. In the current work, the synthesis of a molecularly imprinted biopolymer (MIBP) carrying 4-EPS specific cavities only using the biopolymer polydopamine (PDA) and molybdenum disulfide (MoS2) nanosheets has been reported. The fabricated electrode was prepared using screen-printed carbon electrodes on a polyvinyl chloride substrate. The synthesized material was characterized using several techniques, and electrochemical studies were performed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The DPV technique for the electrochemical sensing of 4-EPS using the fabricated sensor (PDA@MoS2-MIBP) determined a sensitivity of 0.012 µA/ng mL/cm2 and a limit of detection of 30 ng/mL in a broad linear range of 1-2200 ng/mL. Also, the interferent study was performed to evaluate the selectivity of the fabricated sensor along with the control and stability study. Moreover, the performance of the sensor was evaluated in the spiked urine sample, and a comparison was made with the data obtained by ultraperformance liquid chromatography-tandem mass spectroscopy.

Fabrication of Mesoporous Silica Nanoparticle-Decorated Graphene Oxide Sheets for the Effective Removal of Lead (Pb2+) from Water.

Mesoporous silica nanoparticle-decorated graphene oxide nanosheets (MSiO2-GO) were synthesized and characterized for the active removal of lead (Pb2+) from the water. MSiO2 NPs were prepared via an ultrasonication method using tetraethyl orthosilicate (TEOS), and GO sheets were obtained via a modified Hummers' method. X-ray diffraction, UV-vis spectroscopy, Fourier transform infrared spectroscopy, and energy dispersive X-ray spectroscopy specified the composition of MSiO2 NPs and GO sheets. The surface charge and texture of the MSiO2-GO nanosheets were obtained using the ζ-potential technique and by field emission scanning electron microscopy. The relative cytotoxicity test of MSiO2 NPs and MSiO2-GO nanosheets was performed on Murine Raw 264.7 cells before implying the treatment of water. Adsorption of Pb2+ ions on MSiO2-GO nanosheets was examined at various parameters such as different aqueous pH values (2.0-10.0), MSiO2-GO nanosheet doses (3, 5, 10, 15, 20 mg L-1), time intervals (2-30 min), and temperatures (25-45 °C). About 90% of Pb2+ ions were removed from water within 30 min (MSiO2-GO dose: 15 mg L-1; initial Pb2+ ions: 50 mg L-1; temperature: 25 °C; shaking speed: 200 rpm). The maximal uptake of Pb2+ was obtained at solution pH 6.0. Pseudo-first- and pseudo-second-order kinetic rate equations describe the sorption dynamic data. Pb2+ sorption isotherms were modeled using the Freundlich and Langmuir isotherm models. The possible mechanism of binding of Pb2+ ions onto MSiO2-GO nanosheets has been discussed. The exhausted MSiO2-GO nanosheets were successfully regenerated using 0.005 M HNO3 as the desorbing agent.

Polyvinyl alcohol-derived-carbon quantum dots based fluorometric "On-Off" probe for moxifloxacin detection in milk and egg samples.

Unconditional use of antibiotics triggered the process of bacterial resistance and causes major health problems. Nowadays, antibiotics majorly used in animals not only for infection treatment but also as mass promotor. The excess amount of antibiotics residue in animal derived foods which accelerate antibiotic resistance (ABR). So, here, a simple and quick carbon quantum dots(CQDs) based fluorometric "On-Off" probe was developed for detection of moxifloxacin (MOXI) in milk and egg samples. The CQDs emits blue emission and are uniformly distributed with average particle size 5.9 ± 0.22 nm. With MOXI, fluorescence intensity of CQDs at 372 nm decreased due to inner filter effect (IFE) and a new peak appeared at 508 nm correspondence to MOXI. The probe shows linear response with MOXI concentration varies as 0.025 µM - 15.0 µM with lower detection limit (LOD) of 6.34 nM. The real sample applicability test proved that the sensors have excellent efficacy for food applications.

Nano-modified screen-printed electrode-based electrochemical immunosensors for oral cancer biomarker detection in undiluted human serum and saliva samples.

This proposed work reports the development of in-house made conductive ink-based screen-printed electrodes (SPEs) for label-free detection of oral cancer biomarkers. Carbon ink synthesis includes graphite powder, gum arabic, and water. The selectivity test of the fabricated SPE involves immobilizing antibodies specific to biomarkers and challenges with redox-active interference, other serum molecules, and non-target biomarkers. Three different biomarkers, cytokeratin-19 fragment (CYFRA 21-1), interleukin 8 (IL-8), and tumor protein p53 (TP-53), act as target entities for the detection of oral cancer in patients' samples (serum, N = 28, and saliva, N = 16) at an early stage. The standard technique enzyme-linked immunosorbent assay (ELISA) was employed to estimate the concentration of the biomarkers in serum and saliva samples. SPEs contain amine (-NH2) functional groups involved in covalent bonding with the carboxyl (-COOH) groups of antibody molecules. These immunosensors exhibited remarkably lower detection limits of 829.5 pg mL-1, 0.543 pg mL-1, and 1.165 pg mL-1, and excellent sensitivity of 0.935 µA mL pg-1 cm-1, 0.039 µA mL pg-1 cm-1, and 0.008 µA mL pg-1 cm-1 for CYFRA 21-1, IL-8, and TP-53 biomarkers, respectively. This sensing platform does not require any functionalization for biomolecule immobilization. Thus, it is a cost-effective, disposable, flexible, miniaturized, and sensitive strip to detect oral cancer biomarkers.

Granular Hemostatic Composite of Alginate, Calcium, and Zinc for Rapid and Effective Management of Post-Traumatic Hemorrhage.

Post-traumatic hemorrhage, which can result from accidents or battlefield injuries, is a significant global concern due to the high prehospital mortality rate. Substantial efforts have been made to develop hemostatic agents that can effectively reduce hemorrhage in the immediate aftermath of a traumatic event. The present study investigated the potential efficacy of Ca2+ and Zn2+ supplemented sodium alginate-based dry hemostatic particles (SA-CZ DHP) to manage excessive blood loss or post-traumatic hemorrhage. SA-CZ DHP were developed, followed by their physical and biochemical characterization, cytocompatibility and hemocompatibility testing, and critical evaluation of the hemostatic potential in vitro and in vivo. The safe SA-CZ DHP showed high absorption and accelerated blood clotting kinetics with reduced coagulation time (≈70%, p < 0.0001) in whole human blood, observed with insignificant hemolysis and uninterrupted RBC morphology. SA-CZ DHP significantly reduced the mean blood loss (≈90% in SD rats tail incision), and bleeding time (≈60% in BALB/c mice tail incision) was at par with commercially available Celox hemostatic granules. In conclusion, the biocompatible SA-CZ DHP exhibited rapid and effective management of excessive blood loss. It is also pertinent to note that the developed formulation could be a cost-effective alternative to its commercial counterparts.

Gold@Carbon Quantum Dots Nanocomposites Based Two-In-One Sensor: A Novel Approach for Sensitive Detection of Aminoglycosides Antibiotics in Food Samples.

Antibiotics are life-saving drugs for humans, but their unwanted use leads to antibacterial resistance (ABR) and causes serious health problems. The excess of these antibiotics entered to the food chain and caused food contamination. Here, Au@CQDs nanocomposites (NCs) was used as a two-in-one sensor to detect two antibiotics. The color change of AuNCs and fluorescence resonance energy transfer are two distance-dependent phenomena used as sensing mechanisms. In the sensing process, Au@CQDs NCs change their color, enhancing the fluorescence intensity of NCs in the presence of Gentamicin (GENTA) and Kanamycin (KMC) antibiotics. The limit of detection of 116 nM and 133 nM for GENTA and 195 nM and 120 nM for KMC have been achieved with colorimetric and fluorimetric readout, respectively. The practicality of the reported sensor was evaluated in real spiked samples and showed excellent recovery efficiency. Therefore this two-in-one sensor can be used for the food monitoring system.

Amine Functionalized Gadolinium Oxide Nanoparticles-Based Electrochemical Immunosensor for Cholera.

Herein, we report the synthesis and functionalization of gadolinium oxide nanoparticles (Gd2O3 NPs) to fabricate a highly efficient immunosensor for the detection of Vibrio cholera toxin (CT). Gd2O3 NPs were produced in a straightforward manner utilizing the microwave irradiation technique using a domestic microwave oven. X-ray diffraction, transmission electron microscopy, and spectroscopic techniques were used to characterize the structural and physical aspects of Gd2O3 NPs. The Gd2O3 NPs were then functionalized with 3-(Aminopropyl) triethoxysilane (APTES) and electrophoretically deposited onto an ITO-coated glass substrate. The anti-CT monoclonal antibodies were covalently attached to the APTES-Gd2O3/ITO electrode via EDC-NHS chemistry, followed by bovine serum albumin (BSA). For CT detection, electrochemical response experiments using BSA/anti-CT/APTES-Gd2O3/ITO immunoelectrodes were carried out (5-700 ng mL-1). The immunoelectrode demonstrated an outstanding electrochemical reaction against CT, with a sensitivity of 8.37 mA ng-1 mL cm-2 and a detection limit of 1.48 ng mL-1.