Commercial Human Serum Research Articles

Design of a molecularly imprinted polymer sensor modified with saffron-based copper nanoflowers for highly selective and sensitive determination of bortezomib

This work represents the first successful application of a molecularly imprinted polymer (MIP)-based electrochemical sensor for the sensitive and selective determination of the first developed proteasome inhibitor, bortezomib (BOR). BOR is used for the treatment of multiple myeloma, gastrointestinal stromal tumors, and mantle cell lymphoma. It shows its desired effect through the boronate group and can be administered intravenously or subcutaneously. The MIP-based electrochemical sensor design includes the integration of green-synthesized saffron-based copper nanoflowers (CuNFs) from Crocus sativus L. to increase the active surface area and porosity of the glassy carbon electrode (GCE) surface. 2-Acrylamido-2-methyl-1-propanesulfonic acid (AMPS) was selected as the functional monomer along with other MIP components. Detailed characterizations of the developed CuNFs/AMPS/MIP-GCE sensor and CuNFs were performed using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray analysis (EDX), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The indirect measurement approach using 5.0 mM [Fe(CN)6]3–/4– solution was used to determine BOR in the linear range of 2.5 × 10−13 M − 2.5 × 10−12 M (0.25–2.5 pM). The LOD and LOQ values of the sensor obtained at the fM level (29 fM and 96.7 fM), which has a linear response in the commercial human serum sample in the same concentration range, emphasize its sensitivity (1.89 × 1013 and 2.14 × 1013 μA/M for standard solution and serum). The repeatability and reproducibility of the sensor were between 0.87 % and 2.17 %, showing its reliability. The successful performance of the sensor in the presence of metabolites belonging to BOR demonstrates its unique selectivity. The selectivity was demonstrated via relative imprinting factor (IF') values (higher than 3.5) against BOR's metabolites. The stability of the CuNFs/AMPS/MIP-GCE sensor was found to be 5 days.

Comparative study of two MIP-based electrochemical sensors for selective detection and quantification of the antiretroviral drug lopinavir in human serum

Thermal polymerization (TP) and electropolymerization (EP) are the two methods used in this study to explore the molecular imprinting process. To detect the antiviral medication lopinavir (LPV), an inhibitor of enzyme HIV-1 protease that is co-formulated with ritonavir (RTV) to extend its half-life in the body, with greater precision, these methods were merged with an electrochemical sensor. The sensors were created on glassy carbon electrodes (GCE) based on molecularly imprinted polymers (MIP) using TP with methacrylic acid (MAA) functional monomer and EP with p-aminobenzoic acid (PABA) functional monomer. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and electrochemical methods were utilized to examine the technical features of the suggested sensors. For both approaches, the necessary optimization investigations were carried out. Different LPV concentrations, ranging from 1.0 pM to 17.5 pM in drug solution and commercial human serum samples, were used to validate the analytical efficiency of the two sensors and compare their electroanalytical behaviour. For TP-LPV@MIP/GCE and EP-LPV@MIP/GCE, the corresponding limit of detection (LOD) was 2.68 × 10−13 M (0.169 pg mL−1) and 1.79 × 10−13 M (0.113 pg mL−1) in standard solutions, and 2.87 × 10−13 M (0.180 pg mL−1) and 2.91 × 10−13 M (0.183 pg mL−1) in serum samples. For the measurement of LPV in tablet form and serum samples, the proposed TP-LPV@MIP/GCE and EP-LPV@MIP/GCE sensors provide good recovery, demonstrating 99.85–101.16 % and 100.36–100.97 % recovery, respectively. The imprinting factor was utilized to demonstrate the selectivity of the suggested sensors by utilizing several anti-viral drugs that are structurally comparable to LPV. Additionally, the constructed sensors were examined for the potential impacts of interferences and the stability during the storage.

Multi-walled carbon nanotubes functionalized with a new Schiff base containing phenylboronic acid residues: applicationtothe development of a bienzymatic glucose biosensor using a response surface methodology approach.

Aninnovative supramolecular architectureis reportedfor bienzymatic glucose biosensing based on the use of a nanohybrid made of multi-walled carbon nanotubes (MWCNTs) non-covalently functionalized with a Schiff base modified with two phenylboronic acid residues (SB-dBA) as platform for the site-specific immobilization of the glycoproteins glucose oxidase (GOx) and horseradish peroxidase (HRP). The analytical signal was obtained from amperometric experiments at - 0.050V in the presence of 5.0 × 10-4M hydroquinone as redox mediator. The concentration of GOx and HRP and the interaction time between the enzymes and the nanohybrid MWCNT-SB-dBA deposited at glassy carbon electrodes (GCEs) were optimized through a central composite design (CCD)/response surface methodology (RSM). The optimal concentrations of GOx and HRP were 3.0mgmL-1 and 1.50mgmL-1, respectively, while the optimum interaction time was 3.0min. The bienzymatic biosensor presented a sensitivity of (24 ± 2) × 102 µA dL mg-1 ((44 ± 4) × 102 µA M-1), a linear range between 0.06mg dL-1 and 21.6mg dL-1 (3.1µM-1.2mM) (R2 = 0.9991),and detection and quantification limits of 0.02mg dL-1 (1.0µM) and 0.06mg dL-1 (3.1µM), respectively. The reproducibility for five sensors prepared with the same MWCNT-SB-dBA nanohybrid was 6.3%, while the reproducibility for sensors prepared with five different nanohybrids and five electrodes each was 7.9%. The GCE/MWCNT-SB-dBA/GOx-HRP was successfully used for the quantification of glucose in artificial human urine and commercial human serum samples.

THE FABRICATION OF MIP BASED ELECTROCHEMICAL SENSOR FOR THE DETERMINATION OF DOBUTAMINE

Objective: Dobutamine (DBT), one of the most common synthetic catecholamines, is important in the renal, cardiovascular, hormonal, and central nervous systems. In our study, it is proposed to produce the first MIP-based electrochemical sensor for DBT analysis. MIP(DBT)/GCE was developed by electropolymerization of 4-aminobenzoic acid (4-ABA) in the presence of DBT. Analytical performance and validation evaluation were performed on both standard solution and commercial serum samples. Material and Method: DBT was supplied by the Vem pharmaceutical company. For the preparation of 5 mM [Fe(CN)6]3-/4- solution, known amounts of potassium ferricyanide ([K3Fe(CN)6]) and potassium ferrocyanide (K4[Fe(CN)6].3H2O mixed in 0.1 M KCl solution. The 4-ABA was used to create the polymeric film in the presence of DBT. Electrochemical measurements were actualized in IVIUM compactStat.h potentiostat (Eindhoven, The Netherlands) using a three-electrode system consisting of Pt wire, Ag/AgCl reference electrode, and glassy carbon electrode (GCE). Result and Discussion: The MIP(DBT)/GCE sensor was applied to standard solution and commercial serum samples. When DBT concentrations were plotted against ΔI values, a linear response between 1×10-13 and 1×10-12 M was obtained in both environments. LOD results were found to be 0.087×10-13 M and 0.033×10-13 M in standard solution and commercial human serum, respectively. Recovery% and RSD% were found to be 99.68-100.32% and 1.38-1.66%, respectively.

Investigation of electrochemical behaviour and determination of Riociguat with bare GCE and molecularly imprinted polymer-based electrochemical sensor

Pulmonary Arterial Hypertension (PAH) causes death due to ventricular overload and heart failure. Calcium channel blockers, anticoagulants, digoxin and diuretics are the standards of care for PAH. Riociguat (RIO) is an oral soluble guanylate cyclase stimulator approved for the treatment of PAH by World Health Organization (WHO) Group 1 patients. In this study, the electrochemical behavior of RIO was investigated using a bare glassy carbon electrode (GCE). In addition, RIO was determined using GCE and a molecularly imprinted polymer (MIP)-based electrochemical sensor. The MIP-based electrochemical sensor was prepared by photopolymerization of methacrylic acid in the presence of a basic monomer, crosslinker, target molecule, and photoinitiator. The polymer film was characterised by a scanning electron microscope (SEM) and cyclic voltammetry (CV). Under the optimized conditions, the results obtained with GCE and MIP sensor were compared. The analytical performance of GCE and MIP-based electrochemical sensors was evaluated. The linear ranges of RIO were 1.0 × 10–6 – 1.0 × 10–4 M and 1.0 × 10–13 – 1.0 × 10–12 M, with a limit of detection (LOD) of 1.40 × 10–8 M and 2.12 × 10–14 by bare GCE and MIP-based electrochemical sensor using differential pulse voltammetry (DPV), respectively. The results show that the MIP sensor has higher sensitivity than the bare GCE. Both were applied to commercial human serum samples and pharmaceutical dosage forms. The recovery studies were performed, and the recovery% and RSD% results are within the acceptable range. Therefore, the GCE and MIP sensors have good selectivity, accuracy and precision.

Early detection of the ovarian cancer with a label-free and disposable ITO-PET based immunosensor platform

Alpha fetoprotein (AFP), a popular biomarker for ovarian cancer, was the target of this studyto create an immunosensor based on electrochemical impedance spectroscopy (EIS). For this purpose, a disposable Indium tin oxide coated PET (In2O3/SnO2, ITO-PET) electrode was used as a basic electrode for working of the triple electrode system and the electrodes were modified with 3-(Trimethoxy silyl) propyl methacrylate (3- TMSPM) silanization agent. Although there are studies on the determination of AFP, the determination of AFP with a cheap, flexible and sensitive electrode system such as ITO-PET in this study makes the study remarkable. With the designed biosensors, AFP protein determination at a wide concentration range (0.05 pg/mL-100 pg/mL) could be successfully performed. To prove that the designed immunosensor was constructed correctly, linear range, repeatability, reproducibility and regeneration capacity (characterization studies) were investigated. Obtaining successful results in the storage capacity studies of the biosensor, which has high reproducibility and repeatability, showed that it also has potential for commercial use. The high specificity of the biosensor also proves its reliability. Finally, the performance of the biosensor in commercial human serum samples was also evaluated.

Polyaniline-based bovine serum albumin imprinted electrochemical sensor for ultra-trace-level detection in clinical and food safety applications

Monitoring bovine serum albumin (BSA) at ultra-low levels is crucial for clinical and food safety applications, as it plays a significant role in identifying various health conditions and potential risks, necessitating fast, trace-level detection of BSA. This study proposes an approach to address these challenges by employing molecularly imprinted polymer (MIP) to develop an ultra-trace-level and cost-effective BSA sensing platform. The MIP electrochemical sensor was developed using polyaniline (PANI) combined with the protein crosslinker glutaraldehyde (GA) to optimize BSA surface imprinting in the MIP. As a result, the sensor achieves a sensitivity of 1.24 μA/log(pg/mL), with a picomolar detectable limit of 2.3 pg/mL (0.035 pM) and a wide detection range from 20 pg/mL to 200,000 pg/mL (0.303 pM to 3030 pM), making it suitable for clinical and food safety applications. Additionally, the study explores the interaction between an acidic surfactant protein eluent (acetic acid with sodium dodecyl sulfate, AcOH-SDS) and BSA vacant sites, enhancing recognition and re-binding. The PANI-based MIP sensor demonstrates initial feasibility and practicality in commercial milk and real human serum, opening avenues for early disease detection and ensuring food safety in BSA-related immune responses.

Development of ultra-sensitive and selective molecularly imprinted polymer-based electrochemical sensor for L-lactate detection

Lactate detection is important for the food and healthcare industries, and it’s especially important when there’s tissue hypoxia, hepatic illness, bleeding, respiratory failure, or sepsis. A new molecularly imprinted polymer (MIP) based electrochemical sensor was fabricated for differential pulse voltammetric assay of L-lactate (LAC). By using ZIF-8@ZnQ nanoparticles, the number of regions and effective surface area were increased. The polymeric film was obtained using 4 aminobenzoic acid (4-ABA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a cross-linker, 2-hydroxyethyl methacrylate (HEMA) as basic monomers, and 2-hydroxy-2-methylpropiophenone one as initiator. The developed 4-ABA/LAC/ZIF-8@ZnQ@MIP-GCE was morphologically characterised using SEM and electrochemically using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) measurements. A linear range of 0.1–1.0 pM LAC with a detection limit of 29.9 fM was found. Lastly, the MIP-based electrochemical sensor detected LAC in commercial human serum samples.

SH-Alb inhibits phenotype remodeling of pro-fibrotic macrophage to attenuate liver fibrosis through SIRT3-SOD2 axis

Albumin has a variety of biological functions, such as immunomodulatory and antioxidant activity, which depends largely on its thiol activity. However, in clinical trials, the treatment of albumin by injection of commercial human serum albumin (HSA) did not achieve the desired results. Here, we constructed reduced modified albumin (SH-Alb) for in vivo and in vitro experiments to investigate the reasons why HSA did not achieve the expected effects. SH-Alb was found to delay the progression of liver fibrosis in mice by alleviating liver inflammation and oxidative stress. Although R-Alb also has some of the above roles, the effect of SH-Alb is more remarkable. Mechanism studies have shown that SH-Alb reduces the release of pro-inflammatory and pro-fibrotic cytokine through the mitogen-activated protein kinase (MAPK) signaling pathway. In addition, SH-Alb deacetylates SOD2, a key enzyme of mitochondrial reactive oxygen species (ROS) production, by promoting the expression of SIRT3, thereby reducing the accumulation of ROS. Finally, macrophages altered by R-Alb or SH-Alb can inhibit the activation of hepatic stellate cells and endothelial cells, further delaying the progression of liver fibrosis. These results indicate that SH-Alb can remodel the phenotype of macrophages, thereby affecting the intrahepatic microenvironment and delaying the process of liver fibrosis. It provides a good foundation for the application of albumin in clinical treatment.

Selective and Sensitive MIP-Based Electrochemical Sensor for the Analytical Determination of Lanreotide

Lanreotide (LAN) is an analog of somatostatin used to treat acromegaly and neuroendocrine tumors. Considering drug toxicity and the lack of sensitive techniques in drug analysis, the development of sensitive analytical methods is of great importance. During this research, a molecular imprinted polymer (MIP) based film [P(HEMA-MAGA)@MIP/GCE] was prepared by photopolymerization technique for electrochemical determination of LAN for the first time. N-methacryloyl-L-glutamic acid (MAGA) and hydroxyethyl methacrylate (HEMA) were used as functional and basic monomers, respectively. The surface alterations were investigated using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) and the chemical composition of the MIP-based sensor. Theelectrochemical characterization of the modifiedelectrodes was assessed using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Using differential pulse voltammetry (DPV) in standard solution and spiked serum sample of LAN, the linear response range for LAN was obtained as 1.0x10 − 14 M – 1.0x10 − 13 M. The limit of detection (LOD) values were 1.76x10 − 15 M and 1.82x10 − 15 M in water and commercial human serum, respectively. The limit of quantitation(LOQ) values for these were 5.85x10 − 15 M and 6.07x10 − 15 M, respectively. The P(HEMA-MAGA)@MIP/GCE sensor also showed excellent recovery in pharmaceutical preparation and commercial human serum form with of 99.37 % and 99.27 %, respectively, with a good RSD value (0.51–0.73), confirming the accuracy and precision of the sensor. As a control, the non-imprinted polymer (NIP) was also prepared to serve in the same way but without the template. The selectivity experiments were conducted using somatostatin (SOM) and octreotide (OC) as potential competitors to demonstrate the selectivity of the proposed sensor against LAN molecules.

A green perspective for the first electrochemical detection and application of balsalazide via recycled waste core-shell carbon/CdO nanoparticles-based hybrid nanosensor

In this report, a glassy carbon electrode (GCE) modified with carbon-based core–shell structures (CSC) with CdO nanoparticles has been prepared and performed for the electrochemical detection of Balsalazide (BLZ). The electrochemical investigation of BLZ was carefully examined using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) on the bare GCE, and CSC-CdO/GCE. Compared to bare GCE, the proposed CSC-CdO/GCE sensor can remarkably enhance the electrocatalytic activity towards the oxidation of BLZ with an increase in the anodic peak currents. For the optimum of experimental conditions, the influence of supporting electrolyte, the pH, concentration of the nanosensor, and scan rate on the peak potentials and current were investigated on the current response of BLZ before the electrochemical determination of BLZ in commercial human serum and urine samples for GCE, and CSC-CdO/GCE. The limit of detection (LOD) for BLZ in the linear range of 8.00 × 10−9 – 8.00 × 10−5 mol/L was determined as 2.20 × 10−9 mol/L. Recovery measurements assessed the accuracy of the proposed sensor in serum and urine samples. The developed sensor indicated high sensitivity and great stability toward BLZ. Core-shell structures are frequently preferred in sensor applications due to their perfect shapes, active catalytic sites, rapid interfacial transport of pores at different length scales, and their ability to reduce or shorten diffusion action paths. CSC was used as a modification material in this study due to its superior properties and advantages. Since CSC has a high surface area during the electron transfer process, it enables more efficient charge transfer between the electrode and the electrolyte. In the study, CdO nanoparticle modification on the CSC was ensured for a synergistic effect to enhance the surface area, electroactivity, and selectivity. After morphological, physical, and chemical characterization of composite material, electrochemical experiments showed that it is extremely promising because of its wide linear concentration range, low LOD, and nearly no interference with some interfering compounds and ions.

Label-free aptasensor targeting Staphylococcus aureus surface Protein A

The rapid detection of Staphylococcus aureus (S. aureus) is of major importance for the biomedical world in the context where the antimicrobial resistance (AMR), the “silent pandemic”, is considered a global public health threat to humanity. There are various approaches to detect S. aureus either as a whole bacterium or via different biomarkers that indicate the presence of this microorganism. Herein, a label-free aptasensor was designed for the detection of a cellular bacterial wall component, protein A (PrA), as a biomarker for the bacteria presence. A rapid procedure, under 5 min, that involves the deposition of the aptamer at the surface of a gold-based screen-printed electrode was applied followed by a blocking step to prevent non-specific adsorption of the target. After the incubation with PrA, the electrochemical detection was achieved, the aptasensor exhibiting good sensitivity across a wide linear range from 25 nM to 1000 nM, with a limit of detection (LOD) of 8.33 nM in standard solutions of the target. S. aureus was detected in commercial human serum and culture samples displaying a good correlation of the signal and the number of bacteria colonies, in the latter case.

Yeast-Derived Carbon Dot/Cuprous Oxide Composite Electrochemical Sensor for Paracetamol

A novel yeast-derived carbon dot/cuprous oxide nanocomposite (Y-CDs/Cu2O) electrochemical sensor was developed for paracetamol. The Y-CDs were prepared by a one-step hydrothermal treatment and composited with Cu2O nanoparticles via ultrasonication assembly. Transmission electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy were conducted to characterize the morphology and structure of the synthesized nanomaterials systematically. After modification onto a glassy carbon electrode, the resulting sensor displayed excellent electrochemical performances toward paracetamol with a wide linear range (0.5–100 μM), low limit of detection (LOD, 90 nM), good repeatability, and stability (retaining 94% of initial response after 4 weeks). Remarkably, the electrochemical sensor presented good selectivity against potentially coexisting species. Satisfactory results were obtained for the analysis of commercial pharmaceutical tablets and human serum. The attractive sensitivity could be ascribed to the ultra-small size and surface-abundant functional groups of Y-CDs as well as the superior electroconductivity of Cu2O. Thus, the synergistic effect illustrates the Y-CD-Cu2O hybrid structure is promising for constructing high-performance electrochemical sensors.

A disposable impedimetric immunosensor for the analysis of CA125 in human serum samples.

Cancer antigen 125 (CA125) is the most common biomarker used to diagnose and monitor ovarian cancer progression for the last four decades, and precise detection of its levels in blood serum is crucial. In this work, label-free impedimetric CA125 immunosensors were fabricated by using screen-printed carbon electrodes modified with poly toluidine blue (PTB) (in deep eutectic solvent)/gold nanoparticles (AuNP) for the sensitive, environmentally friendly, economical, and practical analysis of CA125. The materials of PTBDES and AuNP were characterized by Fourier Transform Infrared (FT-IR), Scanning Electron Microscope (FE-SEM), and X-ray Diffraction (XRD). The analysis of the CA125 was performed by electrochemical impedance spectroscopy and the developed immunosensor. The immunosensor's repeatability, reproducibility, reusability, selectivity, and storage stability were examined. The developed label-free immunosensor allowed the determination of CA125 in fast, good repeatability and a low limit of detection (1.20pgmL-1) in the linear range of 5-100pgmL-1. The stable surface of the fabricated immunosensor was successfully regenerated ten times. The application of immunosensors in commercial human blood serum was performed, and good recoveries were achieved. The disposable label-free impedimetric CA125 immunosensor developed for the rapid and practical detection of CA125 is a candidate for use in point-of-care tests in clinical applications of ovarian cancer.

Electrochemical capacitive dengue aptasensor using NS1 in undiluted human serum.

Non-structural 1 (NS1) is a protein biomarker that can be found in blood in the early stages of dengue and related infections (Zika and Chikungunya). This study aims to develop a biosensor to selectively quantify NS1 using DNA aptamer co-immobilized on gold electrodes with 6-(ferrocenyl)hexanethiol (FCH) using electrochemical capacitive spectroscopy. This technique uses a redox probe (FCH) immobilized on the self-assembled monolayer to convert impedance into capacitance information. The developed platform was blocked with bovine serum albumin before NS1 exposure and the ratio between aptamers and FCH was optimized. Theaptasensor was tested using commercial NS1 serotype 4 in phosphate-buffered saline and commercial undiluted human serum. Using the optimum applied potential provideshigh sensitivity (3 and 4 nF per decade) and low limit of detection (30.9 and 41.8fg/mL) with a large linear range (10pg to 1µg/mL and 10pg to 100ng/mL, respectively). Both results exhibit a residual standard deviation value < 1%. The results suggested that this aptasensor was capable of detecting NS1 in the clinical range and can be applied to any other specific aptamer with FCH, opening the path for label-free miniaturized point-of-care devices with high sensitivity and specificity.

BİR İNFLUENZA VİRÜSÜ NÖRAMİNİDAZ İNHİBİTÖRÜ OLAN PERAMIVİR’İN SAPTANMASI İÇİN MOLEKÜLER BASKI POLİMER İLE ELEKTROKİMYASAL SENSÖRÜN GELİŞTİRİLMESİ

Objective: Influenza viruses are the most common cause of influenza. Antiviral drugs prevent the spread of the virus through the infected cells. Peramivir is one of the antiviral drugs that is an inhibitor of influenza virus neuraminidase. In our study, we aimed to develop a MIP-based electrochemical sensor to determine Peramivir. This study is the first to create an electrochemical sensor for Peramivir. MIP(PERA)/GCE was fabricated with the electropolymerization of 4-aminophenol (4-AP) and ortophenilendiamine (o-PD) in the presence of Peramivir. The developed MIP(PERA)/GCE was applied to the commercial serum sample for analysis of Peramivir. Material and Method: PERA is supplied by Tobio Novelpharma pharmaceutical company (İstanbul, Türkiye). Potassium ferricyanide ([K3Fe(CN)6]), potassium ferrocyanide (K4[Fe(CN)6].3H2O), and potassium chloride (KCl), 4-aminophenol (4-AP) and ortophenilendiamine (o-PD), commercial human serum sample, dopamine, ascorbic acid, uric acid, paracetamol, KNO3, Na2SO4 ve MgCl2 were obtained from Sigma-Aldrich (St. Louis, Missouri, USA). Methanol, acetic acid, oxalic acid, hydrochloric acid, acetonitrile, sodium hydroxide, and ethanol were purchased by Merck. The redox process was investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) by the Dropsens μStat 400 Bipotantiostat/ Galvanostat (Metrohm, Herisau, Switzerland). Three-electrode systems consisted of a glassy carbon working electrode (GCE, 3mm2, BASi, USA), a saturated Ag/AgCl reference electrode, and a Pt wire. Result and Discussion: The sensor exhibits a linear range of 1-10 pM with a detection limit of 0.158 pM. The MIP(PERA)/GCE sensor could detect PERA from commercial serum samples with a high recovery of 101.81%.

Quartz tuning fork biosensor: A potential tool for SARS-CoV-2 detection

Portable, fast, and practical devices are important in the fight against epidemic diseases. The lack of readily available small-scale commercial solutions prompted us to delve deeper into this research effort. Investment in Quartz Tuning Fork (QTF)-based biosensor research is significant due to its seamless integration with miniaturised and portable devices. Within the scope of this study, a new, cost-effective, and versatile frequency analyser designed for detecting diseases, compatible with screens of different sizes, has been introduced. The modified QTF sensor occured mass-sensitive SARS-CoV-2 nucleocapsid protein (SARS-NP) detection with remarkable simplicity, sensitivity, and selectivity. The developed QTF-based biosensor has an impressive linear detection range ranging from 5 to 200 ng/mL and an exceptionally low limit of detection (LOD) value of 1.72 ng/mL. The sensitivity of the developed QTF-based biosensor was obtained as 50 Hz/1 μM. The biosensor response was then evaluated in commercial human serum sample. After 15 days of storage, these biosensors retained approximately 93.7 % of their initial activity. Additionally, a Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) comprehensively characterised the electrode surface.

Designing an electrochemical sensor based on ZnO nanoparticle-supported molecularly imprinted polymer for ultra-sensitive and selective detection of sorafenib

BackgroundSorafenib (SOR) is a multikinase inhibitor anticancer drug that is used in treating non-small cell lung cancer. In this work, we focused on developing nanomaterial-supported smart porous interfaces by following the molecular imprinting approach for the selective determination of SOR. Determination-based studies in the literature for SOR are limited, and they are chromatographic techniques-based; hence, there is a need in the literature to elaborate the selective and sensitive analysis/monitoring of SOR in both biological and pharmaceutical samples with more studies. ResultsThe results showed that adding ZnO NPs enhanced the signal five times compared to the solo molecularly imprinted polymer (MIP). Under the optimized conditions, ZnO/AMPS@MIP-GCE showed a linear response in the concentration range between 1.0 × 10−12 and 1.0 × 10−11 M with LOD and LOQ values of 2.25 × 10−13 M and 7.51 × 10−13 M, respectively, in the serum sample. The selectivity study was conducted against common cations, anions, and compounds such as dopamine, paracetamol, ascorbic acid, and uric acid. Also, the imprinting factor (IF) analysis was performed on selected drug substances having structural similarities to SOR and the relative IF values of regorafenib, leflunomide, teriflunomide, nilotinib, axitinib, and dasatinib indicated the selectivity of the developed sensor for SOR. Finally, ZnO/AMPS@MIP-GCE was implemented to determine SOR in the spiked commercial human serum samples and tablet dosage form with bias% between −0.43 and + 0.66. Significance and noveltyThis study is the first electrochemical study for the determination of SOR, and thanks to the ZnO NPs supported MIP sensor, it stands out in terms of both high sensitivity and superior selectivity. Also, this designed sensor provides controlled orientation of the template and complete removal of templates in a one-step process, allowing extremely low detection and quantification limits.

Comparative MIP sensor technique: photopolymerization or thermal polymerization for the sensitive determinationof anticancer drug Regorafenib in different matrixes.

Regorafenib (REG) is a diphenylurea derivative oral multikinase inhibitor. It plays an important role in the treatment of colorectal cancer, metastatic gastrointestinal stromal tumors, and hepatocellular carcinoma. Molecularly imprinted polymer (MIP) based glassy carbon electrodes (GCE) were fabricated using photopolymerization (PP) and thermal polymerization (TP) methods. The characterizations of the proposed sensors were investigated by electrochemical techniques, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Several parameters were studied in detail for the optimum conditions of MIP-based sensors, such as dropping volume, photopolymerization and thermal polymerization durations, removal medium and time, and rebinding time. Both sensors' analytical validation and electroanalytical performance comparison were made in different REG concentrations ranging between 0.1 nM and 2.5 nM in standard solution and commercial human serum samples. The limit of detection (LOD) of PP-REG@MIP/GCE and TP-REG@MIP/GCE were 9.13 × 10-12 M and 1.44 × 10-11 M in standard solutions and 2.04 × 10-11 M and 2.02 × 10-11 M in serum samples, respectively. The applicability of the proposed sensors was tested using commercial human serum samples and pharmaceutical form of REG with high recovery values (PP-REG@MIP/GCE and TP REG@MIP/GCE sensors, 99.56-101.59%, respectively). The selectivity of the sensor for REGwas investigatedin the presence of similar molecules: Sorafenib, Sunitinib, Nilotinib, and Imatinib. The developed techniques and sensors checked the possible biological compounds and ions' effects and storage stability.

Boron nitride nanosheet modified amperometric biosensor for uric acid determination

In this study, enzyme-modified boron nitride nanosheets as a catalytic two-dimension material for the sensor application developed for the first time. In this developed system, uricase interacted with B-N groups by the two-dimensional structure of the boron nitride layer. In this way, a unique catalytic structure was created by binding uricase to B-N groups, and this structure was protected by NafionTM. The developed enzyme-based biosensor exhibited a wide linear detection range (5–3000 µM), and a low limit of detection and quantitation values (0.14 µM and 0.46 µM, respectively) for uric acid. Also, the developed system performed good reproducibility, reusability, high selectivity, sensitivity, low Km value, and excellent shelf-life properties. Furthermore, this enzyme-based biosensor has successfully identified uric acid in commercial human serum with a high recovery rate. It has promised rapid, high sensitivity and real serum applications to determine the level of uric acid.