Human Blood Serum Samples Research Articles

CuCoP@Cu(OH)2 core-shell nanostructure as a robust electrochemical sensor for glucose detection in biological and beverage samples

The direct growth of transition metal phosphides with a highly accessible surfaces and copper electroactive centers can be considered as an efficient method to modify the electrode surface and use them as an electrochemical sensor. Herein, a direct, efficient, low-cost and rapid method is used for growing core–shell nanostructures of CuCoP nanosheets on Cu(OH)2 nanotubes (pre-deposited on glassy carbon electrode). The Cu(OH)2 nanotubes act as a conductive intermediate and directing agent to obtain CuCoP@Cu(OH)2 core–shell structure. The growth of CuCoP on Cu(OH)2 nanotubes provides structural stability and large surface area as well as increases the availability of the catalytic sites for diffusion of analyte species and electrolyte ions into the electrode surface, leading to excellent electrocatalytic performance towards glucose electro-oxidation. The amperometric studies of glucose for electrode modified with CuCoP@Cu(OH)2 showed two linear ranges of 0.001 mM to 0.105 mM and 0.105 mM to 2.530 mM with very high sensitivities of 8351 and 3932 μA/mM.cm2, respectively. Also, the fabricated sensing platform exhibited excellent selectivity and resistance to chloride ion poisoning, good reproducibility and repeatability, as well as low detection limit of 2.3 μM. In addition, the modified electrode showed a very quick reaction time of 2 s. Finally, to assess the usability of the designed non-enzymatic sensor in practical applications, the as-prepared nanocomposite was examined for measuring the glucose content in biological samples such as human blood serum, saliva, and beverage samples. The outcomes showed that the designed platform can be used as a reliable and efficient sensor for accurate detection and measurement of glucose in real samples.

Synergistic integration of Ni-metal organic framework/SnS2 nanocomposite and nickel foam electrode for ultrasensitive and selective electrochemical detection of albumin in simulated human blood serum

Albumin is a vital blood protein responsible for transporting metabolites and drugs throughout the body and serves as a potential biomarker for various medical conditions, including inflammatory, cardiovascular, and renal issues. This report details the fabrication of Ni-metal organic framework/SnS2 nanocomposite modified nickel foam electrochemical sensor for highly sensitive and selective non enzymatic detection of albumin in simulated human blood serum samples. Ni-metal organic framework/SnS2 nanocomposite was synthesized using solvothermal technique by combining Ni-metal–organic framework (MOF) with conductive SnS2 leading to the formation of a highly porous material with reduced toxicity and excellent electrical conductivity. Detailed surface morphology and chemical bonding of the Ni-MOF/SnS2 nanocomposite was studied using scanning electron microscopy, transmission electron microscopy, Fourier transform infra-red, and Raman analysis. The Ni-MOF/SnS2 nanocomposite coated on Ni foam electrode demonstrated outstanding electrochemical performance, with a low limit of detection (0.44 μM) and high sensitivity (1.3 μA/pM/cm2) throughout a broad linear range (100 pM–10 mM). The remarkable sensor performance is achieved through the synthesis of a Ni-MOF/SnS2 nanocomposite, enhancing electrocatalytic activity for efficient albumin redox reactions. The enhanced performance can be attributed due to the structural porosity of nickel foam and Ni-metal organic framework, which favours increased surface area for albumin interaction. The presence of SnS2 shows stability in acidic and neutral solutions due to high surface to volume ratio which in turn improves sensitivity of the sensing material. The sensor exhibited commendable selectivity, maintaining its performance even when exposed to potential interfering substances like glucose, ascorbic acid, K+, Na+, uric acid, and urea. The sensor effectively demonstrates its accuracy in detecting albumin in real samples, showcasing substantial recovery percentages of 105.1%, 110.28%, and 91.16%.

Dispersive Solid Phase Extraction/Back-Extraction Using Carbon Nanotubes as Sorbent for HPLC/UV Determination of Ibuprofen in Human Blood Serum Samples

Dispersive Solid Phase Extraction/Back-Extraction Using Carbon Nanotubes as Sorbent for HPLC/UV Determination of Ibuprofen in Human Blood Serum Samples

Development of molybdenum trioxide based modified graphite sheet electrodes for enhancing the electrochemical sensing of dopamine

Electrochemical detection of dopamine is crucial in the early stages of Parkinson's and Alzheimer's disease diagnosis. In this paper, we have developed modified electrodes based on molybdenum oxide (MoO3) grown on graphite sheet (GS), which was investigated for its ability to detect dopamine sensitively and selectively. The MoO3/GS electrodes were prepared by thermal evaporation of MoO3 on GS sheets followed by annealing at different temperatures (RT and annealing temperatures of 100 °C, 200 °C, 300 °C, 400 °C and 500 °C). The electrodes were analysed using XRD, Raman, FESEM and HRTEM. Compared to other electrodes, the modified MoO3/GS electrode annealed at 500 °C showed more significant charge transfer and increased selectivity and sensitivity in the electrochemical detection of dopamine. The findings showed a significant sensitivity of 85.71 μA. μM−1·cm−2 for the linear range of 1–10 nM and the lowest detection limit of 2.71 nM were achieved from the dopamine sensing. The developed electrode successfully detected dopamine in human blood serum and urine samples with respectable recovery rates.

Detection of SARS-CoV-2 N protein using AgNPs-modified aligned silicon nanowires BioSERS chip.

The SARS-CoV-2 (COVID-19) pandemic had a strong impact on societies and economies worldwide and tests for high-performance detection of SARS-CoV-2 biomarkers are still needed for potential future outbreaks of the disease. In this paper, we present the different steps for the design of an aptamer-based surface-enhanced Raman scattering (BioSERS) sensing chip capable of detecting the coronavirus nucleocapsid protein (N protein) in spiked phosphate-buffered solutions and real samples of human blood serum. Optimization of the preparation steps in terms of the aptamer concentration used for the functionalization of the silver nanoparticles, time for affixing the aptamer, incubation time with target protein, and insulation of the silver active surface with cysteamine, led to a sensitive BioSERS chip, which was able to detect the N protein in the range from 1 to 75 ng mL-1 in spiked phosphate-buffered solutions with a detection limit of 1 ng mL-1 within 30 min. Furthermore, the BioSERS chip was used to detect the target protein in scarcely spiked human serum. This study demonstrates the possibility of a clinical application that can improve the detection limit and accuracy of the currently commercialized SARS-CoV-2 immunodiagnostic kit. Additionally, the system is modular and can be applied to detect other proteins by only changing the aptamer.

Two-dimensional oxygen-deficient ZnO1-x nanosheet as a highly selective and sensitive fluorescence probe for ferritin detection: the electron transfer biosensor (ETBS).

Iron proteins are of great scientific interest due to their importance as an excellent biomarker for human diseases. Ferritin (Fe3+), being an iron-rich blood protein, is related to various diseases like anemia and cancer. For the first time, we have developed a highly sensitive and selective ferritin biosensor based on fluorescent oxygen-deficient zinc oxide nanosheets through hydrothermal and probe-ultrasonication combined methods. The fluorescence study showed an intense bluish-green fluorescence at λex = 370 nm, after optimization at different excitation wavelengths. In addition, the fluorescence of ZnO1-x nanosheets can be efficiently quenched due to electron transfer reactions in order to achieve quantification analysis. The limit of detection (LOD) was calculated to be 0.015 nM (7.2 ng mL-1) with high linearity (R2 = 0.9930). In addition, the real-world application of the proposed biosensor has been performed on human blood serum samples in the presence of various interfering analytes showing high selectivity and sensitivity with a regression value R2 = 0.9980 indicating the current approach is an excellent biosensor platform.

Bio-conjugated carbon dots for the bimodal detection of prostate cancer biomarkers via sandwich fluorescence and electrochemical immunoassays.

Bimodal detection facilitates the accurate and reliable detection of cancer biomarkers, which can assist in the early diagnosis of cancer. Herein, S-doped carbon dots (OCDs) with a size of 3 nm and blue emission were synthesized by the hydrothermal treatment of onion extract. The S-doped carbon dots were bioconjugated with an antibody (OCDs@PSAAbHRP) to design a nanoprobe for the detection of prostate specific antigen (PSA), an important serum based prostate cancer biomarker. The detection probe enabled the biomodal assay of PSA via fluorescence immunoassay (FIA) and electrochemical immunoassay (ECIA). In both assays, polyethylenimine stabilized polyaniline nanoparticles (PNPs) were used as the immobilization matrix, which played a major role in widening the linear range of biosensors (0.1 to 100 ng ml-1 for ECIA and 5 to 120 ng ml-1 for FIA). Paper-based and smartphone-integrated fluorescence immuno-array developed using the OCDs@PSAAbHRP detection probe provided cost-effective and rapid detection, while the electrochemical immunoassay provided a high sensitivity (7.8 μA ng-1 ml-1 cm-2) and low detection limit (38 pg ml-1) for PSA detection. The role of OCDs in enhancing the sensor performance was deciphered by carrying out detailed electrochemical studies with HRP enzyme-loaded OCDs. The biosensor was used to detect PSA in human blood serum samples and the results were consistent with conventional techniques. Owing to its analytical properties coupled with simplicity, cost-effectiveness, and portability, the bimodal sensor system has potential for application in clinical analysis.

A hemin/rGO/MWCNT nanocomposite-based dual signal electrochemical aptasensor for sensitive detection of NSE.

Neuron-specific enolase (NSE), a tumor marker of small cell lung cancer (SCLC), has high application value in the early diagnosis of SCLC. In this study, a dual signal electrochemical aptasensor for NSE was constructed based on hemin/reduced graphene oxide/multi-walled carbon nanotube (H-rGO-MWCNT) nanocomposites. Hemin played a dual role, functioning not only as an in situ electrochemical probe but also exhibiting excellent peroxidase-like properties, effectively catalyzing the electroreduction of H2O2. Reduced graphene oxide and multi-walled carbon nanotubes exhibited excellent conductivity. Through their binding with hemin, the nanocomposites achieved a larger specific surface area, providing numerous active sites for capturing the NSE aptamer. In the presence of NSE, the specific adsorption between the antigen and the aptamer formed a stable antigen-aptamer structure, which inhibited the performance of hemin, resulting in the weakening of the electrochemical signals of hemin and H2O2. Leveraging these characteristics, the sensitive and cost-effective dual-signal electrochemical aptasensor has been fabricated for the detection of NSE. One signal corresponded to differential pulse voltammetry (DPV) of hemin, while the other signal was derived from chronoamperometry, capturing the catalytic reduction of H2O2. The linear ranges for NSE were 1 pg mL-1 to 1 μg mL-1 and 100 pg mL-1 to 100 ng mL-1 with the limit of detection (LOD) of 0.21 pg mL-1 and 11.22 pg mL-1 by DPV and chronoamperometry, respectively. In addition, this aptasensor exhibited good reproducibility, stability and specificity. The recovery of NSE in human blood serum samples was from 89% to 131%. It provided a promising strategy for the detection of NSE in clinical diagnostics.

Strategic electrochemical oxidation of vinblastin sulfate (an anticancer drug) via PVP-functionalized strontium oxide nanoparticles.

Cancer is a primary cause of death worldwide, and considerably impacts mortality rates in low- and middle-income countries. The rise in chemotherapeutic patients and toxicity of cytotoxic agents highlight the need for reliable analytical methods to detect these compounds. The current study presents a simple and straightforward method for producing polyvinylpyrrolidone functionalized strontium oxide nanoparticles (PVP-SrO NPs). The synthesized PVP-SrO NPs were applied as a sensitive sensor to detect vinblastin sulfate (VNB) (an anticancer drug). The synthesized PVP-SrO NPs were characterized using different characterization techniques. Fourier transform infrared spectroscopy (FTIR) confirms the functionality of synthesized PVP-SrO NPs. The sharp intense peaks of X-ray diffraction spectroscopy (XRD) confirm the crystalline nature of NPs, scanning electron microscopy (SEM) confirm the nanobeads like morphology, and energy dispersive spectroscopy (EDS) reveals the presence of Sr and O at 68.3% and 23% respectively. The electrochemical impedance spectroscopy and cyclic voltammetry studies revealed that the PVP-SrO/GCE is more conductive than bare GCE with an R ct value of 960.4 Ω compared to 2440 Ω. The sensor exhibited a wide linear dynamic range for VNB (0.05 to 60 μM) with low LOD 0.005 μM, and LOD 0.017 μM. The proposed sensor was successfully used for monitoring VNB in human blood serum samples with a satisfactory percent recovery from 96% to 103%. The fabricated sensor exhibits better performance than the reported sensors in terms of processing, simplicity, cost-effectiveness, energy consumption, and enhanced efficacy in a very short time.

Screen printed 3D microfluidic paper-based and modifier-free electroanalytical device for clozapine sensing.

The increasing demand in healthcare for accessible and cost-effective analytical tools is driving the development of reliable platforms to the customization of therapy according to individual patient drug serum levels, e.g. of anti-psychotics in schizophrenia. A modifier-free microfluidic paper-based electroanalytical device (μPED) holds promise as a portable, sensitive, and affordable solution. While many studies focus on the working electrode catalysts, improvements by engineering aspects e.g. of the electrode arrangement are less reported. In our study, we demonstrate the enhanced capabilities of the 3D electrode layout of μPED compared to 2D μPED arrangements. We especially show that screen printing can be employed to prepare 3D μPEDs. We conducted a comparison of different 2D and 3D electrode arrangements utilizing cyclic voltammetry in [Fe(CN)6]3-/4-, along with square-wave voltammetry for clozapine (CLZ) sensing. Our findings reveal that the utilization of the 3D μPED leads to an increase in both the electrochemically active surface area and the electron transfer rate. Consequently, this enhancement contributes to improve sensitivity in the CLZ sensing. The 3D μPED clearly outperforms the 2D μPED arrangement in terms of signal strength. With the 3D μPED under the optimized conditions, a linear dose-response for a concentration range from 7.0 to 100 μM was achieved. The limit of detection and sensitivity was determined to be 1.47 μM and 1.69 μA μM-1 cm-2, respectively. This evaluation is conducted in the context of detection and determination of CLZ in a human blood serum sample. These findings underscore the potential of the 3D μPED for future applications in pharmacokinetic analyses and clinical tests to personalize the management of schizophrenia.

Human serum proteomics reveals a molecular signature after one night of sleep deprivation.

Sleep deprivation is highly prevalent and caused by conditions such as night shift work or illnesses like obstructive sleep apnea. Compromised sleep affects cardiovascular-, immune-, and neuronal systems. Recently, we published human serum proteome changes after a simulated night shift. This pilot proteomic study aimed to further explore changes in human blood serum after 6 hours of sleep deprivation at night. Human blood serum samples from eight self-declared healthy females were analyzed using Orbitrap Eclipse mass spectrometry (MS-MS) and high-pressure liquid chromatography. We used a within-participant design, in which the samples were taken after 6 hours of sleep at night and after 6 hours of sleep deprivation the following night. Systems biological databases and bioinformatic software were used to analyze the data and comparative analysis were done with other published sleep-related proteomic datasets. Out of 494 proteins, 66 were found to be differentially expressed proteins (DEPs) after 6 hours of sleep deprivation. Functional enrichment analysis revealed the associations of these DEPs with several biological functions related to the altered regulation of cellular processes such as platelet degranulation and blood coagulation, as well as associations with different curated gene sets. This study presents serum proteomic changes after 6 hours of sleep deprivation, supports previous findings showing that short sleep deprivation affects several biological processes, and reveals a molecular signature of proteins related to pathological conditions such as altered coagulation and platelet function, impaired lipid and immune function, and cell proliferation. Data are available via ProteomeXchange with identifier PXD045729. This paper is part of the Genetic and other molecular underpinnings of sleep, sleep disorders, and circadian rhythms including translational approaches Collection.

A novel Ga2O3-doped ZnO decorated SWCNT nanocomposite based amperometric sensor for efficient detection of dopamine in real samples

Our current research focuses on developing an efficient electrochemical Dopamine sensor for diagnosing neurological disorders related to abnormal Dopamine levels. We utilized a Ga2O3-doped ZnO decorated SWCNT (Ga2O3·ZnO@SWCNT) nanocomposite to modify a glassy carbon electrode. The structure and morphology of the Ga2O3·ZnO@SWCNT nanocomposite was examined utilizing a variety of approaches to ensure of their appropriateness as the sensing nanomaterial. The sensor effectively detects Dopamine within a wide range (1.0–2056 μM) in neutral phosphate buffer solution, exhibiting high sensitivity (0.2536 μAμM−1cm−2) and a practical detection limit (0.052 μM). It accurately quantifies Dopamine in human blood serum and commercial dopamine injection samples, displaying excellent reproducibility, repeatability, and stability. This proposed Dopamine sensor proves to be a reliable tool for Dopamine determination.

Selective square wave voltammetric determination of tinidazole in pharmaceutical formulations, and human urine samples using poly(bis(2,2′-bipyridine)diresorcinolateruthenium(III) chloride) modified glassy carbon electrode

This study reports the determination of Tinidazole (TDL) using a modified glassy carbon electrode, poly(bis(2,2′-bipyridine)diresorcinateruthenium(III) chloride) (poly(BBPDRRuC)/GCE) by a newly synthesized mixed ligand complex, bis-(2,2′-bipyridine)diresorcinateruthenium(III) chloride(BBPDRRuC). Electrochemical impedance spectroscopy (EIS) and cyclic voltamettry (CV) results demonstrated modification of the surface of the electrode by a conductive, and electroactive polymer film leading to an enhanced effective electrode surface area and their electrocatalytic role. Appearance of an irreversible reductive peak at much reduced potential with four folds current enhancement at poly(BBPDRRuC)/GCE showed the catalytic effect of the modifier by reduction of TDL. Square wave voltammetry current response of poly(BBPDRRuC)/GCE showed linear dependence on concentration of TDL in the range 10−8˗ 3.0 × 10−4 M with LoD and LoQ of 2.5 nM, and 8.2 nM, respectively. The TDL level in the studied tablet brands were in the range 96.6–101.1% of their labeled values. Spike recovery results in tablet, and human blood serum samples were in the range 98.3˗100.4%, and 98.85 ˗ 99.89%, respectively, and interference recovery results with <4.5% error. The developed method required a simple electrode modification step, a relatively chip, an easily available and non-toxic modifier, provides the least LoD, and reasonably wider linear dynamic range, and had excellent performance for the determination of TDL in tablet formulation and serum samples as compared with recently reported voltammetric methods.

Cadmium selenium quantum dot based nanosensor with femto molar level sensitivity for the detection of the pesticide endosulfan

Endosulfan (6,7,8,9,10,10-Hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine-3-oxide) is an off-patent insecticide used in agricultural farms. Its usage as a pesticide has become highly controversial over the last few decades. This is due to its reported hazardous nature to health and side effects like growth retardation, hydrocephalus, and undesired changes in the male and female hormones leading to complications in sexual maturity. Endosulfan is the main culprit among all pesticide poisoning incidents around the world. Though the usage of this dreaded pesticide is banned by most countries, the high stability of this molecule to withstand degradation for a long period poses a threat to mankind even today. So, it has become highly essential to detect the presence of this poisonous pesticide in the drinking water and milk around these places. It is also advisable to check the presence of this toxic material in the blood of the population living in and around these places so that an early and appropriate management strategy can be adopted. With this aim, we have developed a sensor for endosulfan that displayed high selectivity and sensitivity among all other common analytes in water and biological samples, with a wide linear concentration range (2 fM to 2 mM), a low detection limit (2 fM), and rapid response. A citrate-functionalized cadmium-selenium quantum dot was used for this purpose, which showed a concentration-dependent fluorescence enhancement, enabling easy and sensitive sensing. This sensor was utilized to detect endosulfan in different sources of water, human blood serum, and milk samples with good recoveries. It is also noted that the quantum dot forms a stable complex with endosulfan and is easy to separate from the contaminated source, paving the way for purifying the contaminated water. More detailed tests and validation of the sensor are needed to confirm these observations.

A new strategy to build electrochemical enzymatic biosensors using a nanohybrid material based on carbon nanotubes and a rationally designed schiff base containing boronic acid

We report a nanohybrid material obtained by non-covalent functionalization of multi-walled carbon nanotubes (MWCNTs) with the new ligand (((1E,1′E)-(naphthalene-2,3-diylbis(azaneylylidene))bis(methaneylylidenedene)) bis(4-hydroxy-3,1-phenylene))diboronic acid (SB-dBA), rationally designed to mimic some recognition properties of biomolecules like concanavalin A, for the development of electrochemical biosensors based on the use of glycobiomolecules as biorecognition element. We present, as a proof-of-concept, a hydrogen peroxide biosensor obtained by anchoring horseradish peroxidase (HRP) at a glassy carbon electrode (GCE) modified with the nanohybrid prepared by sonication of 2.0 mg mL−1 MWCNTs and 0.50 mg mL−1 SB-dBA in N,N-dimethyl formamide (DMF) for 30 min. The hydrogen peroxide biosensing was performed at −0.050 V in the presence of 5.0 × 10−4 M hydroquinone. The analytical characteristics of the resulting biosensor are the following: linear range between 0.175 μM and 6.12 μM, detection limit of 58 nM, and reproducibility of 2.0 % using the same nanohybrid (6 biosensors), and 9.0 % using three different nanohybrids. The sensor was successfully used to quantify hydrogen peroxide in enriched milk and human blood serum samples and in a commercial disinfector.

Ni-P nanosheets derived from a metal–organic framework containing triptycene ligand: A high-performance electrochemical sensor for glucose determination

The synthesis of hierarchical nanostructures using transition metal phosphides (TMPs) derived from metal-organic frameworks (MOFs) has shown good potential in the design of electrochemical sensors. Trypticenes have become attractive organic ligands in the synthesis of MOFs due to their favorable properties. In this study, first, a new MOF using nickel and 2,3,6,7,14,15-hexahydroxy triptycene (Ni-HHTT) has been synthesized through a simple hydrothermal method on nickel foam (NF). Then, during the phosphidation process in an N2 atmosphere, the Ni-HHTT precursor synthesized on nickel foam (Ni-HHTT/NF) was converted into MOFs-derived Ni-P/NF and used as an electrocatalytic sensor in glucose sensing. The fabricated non-enzymatic glucose sensor has a wide concentration range including 0.5–1700 µM and 1700–4100 μM with a low detection limit (0.15 µM). This sensor has advantages such as high sensitivity, accuracy, fast response time (Δt<1.5s), stability, and cost-effectiveness. In addition, the performance of the proposed sensor for measuring glucose in human blood serum samples was evaluated as satisfactory. The proposed strategy provides a new idea for the development of MOF materials based on trypticenes scaffolds and their transition metal phosphide derivatives.

Gum Arabic-mediated synthesis of silver nanoparticles for their applications as colorimetric and SERS-based detection of hydrogen peroxide.

We report on the one-step green method to synthesize Gum Arabic stabilized silver nanoparticles (GA-Ag NPs). The synthesized particles are monodispersed and in the size range of 15-20nm. The synthesized Ag NPs are used as a colorimetric sensor for the detection of H2O2 and glucose with a detection limit of 11.7nM and 0.13µM, respectively. The sensor has also been used for the detection of H2O2 in water samples and glucose in human blood serum samples. The GA-Ag NPs decorated on filter paper have also shown excellent SERS activity for the detection of H2O2 with a detection limit of 0.56µM.

Real-time detection of sorafenib in human serum samples: An evaluation study via electrochemical sensing probe fabricated with silver stannate

BackgroundIn this present work we are aiming to develop an Ag2SnO3 based electrochemical sensor for the detection of kinase inhibitor sorafenib (SRF). The detection of such cancer drugs is important to monitor on the lab scale. The employed Ag2SnO3 with good electrical conductivity, catalytic activity, easier preparation method, earth-abundant nature, and noteworthy features make it more vital as electrode material for sensing SRF. MethodsThe Ag2SnO3 was prepared via hydrothermal method and then characterized with XRD, and XPS analysis to extend its structural presence better. The FESEM analysis was also studied to know the morphology of Ag2SnO3 with the elemental presence verified with EDAX and mapping analysis. The support of Ag2SnO3 over the GCE surface aided the study in better understanding the reaction kinetics with SRF at the electrode interface. The serum samples from patients with SRF intake for different time periods were collected and analyzed for electrochemical performances. Significant findingsThe electrochemical response as recorded provides the presence of SRF in serum samples in comparison with the non-intake of SRF. The SRF analysis studied with the DPV technique with a linear range of about 0.49 to 167.41 µM showed a good response at Ag2SnO3/GCE. Thus, the present study highlights the detection of SRF in human blood serum samples with a lower detection limit 0.043 µM and a good sensitivity of 0.988 μA μM−1 cm2. The presence of SRF was also identified and compared with the initial day of intake. The Ag2SnO3 with high surface area and high conductivity effectively improved the performance.

Graphitic carbon nitride (g–C3N4)-based electrochemical sensors for the determination of antiviral drug acyclovir

Acyclovir (ACR) is an antiviral drug used to treat chickenpox, shingles, and herpes infections in various parts of the body, including infants. It shortens illness duration and reduces symptoms, but may cause kidney damage and allergic reactions in some individuals. It may also be beneficial for those with compromised immune systems. ACR, despite its positive attributes, can cause kidney damage and allergic reactions in some individuals, requiring careful observation and monitoring. ACR was detected electrochemically in this work using graphitic carbon nitride (g-C3N4), which was effectively synthesized. Energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman, Fourier-transform infrared (FT-IR), field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HR-TEM) techniques were used to characterize the synthesized g-C3N4. To monitor ACR, g-C3N4 combined with pure carbon paste (g-C3N4/CPE) was used in voltammetric techniques. The sensor's ability to detect the ACR via g-C3N4 was investigated utilizing the amperometric i-t curve method. Electrochemical impedance spectroscopy (EIS) was used to examine the electrochemical characteristics of various electrodes. The Rct of the bare glassy carbon electrode (GCE), the bare CPE, and the g-C3N4/CPE were, respectively, 12770Ω, 3794Ω, and 3114Ω. From 10 μM to 80 μM ACR concentration, the current response rose linearly. The constructed sensor had an exceptional detection limit of 3.52 nM. By introducing 100 μM concentrations of a variety of common interferents to the ACR solution during the measurement, it was possible to evaluate the impact of several foreign interferents on the outcomes at the g-C3N4. The electrochemical behavior of ACR was investigated in respect to several electrokinetic variables. The mechanism of potential electrochemical oxidation was demonstrated. The developed g-C3N4/CPE effectively identified ACR quantitatively in samples of human blood serum and urine.

LC-MS/MS Quantitation of HILIC-Enriched N-glycopeptides Derived from Low-Abundance Serum Glycoproteins in Patients with Narcolepsy Type 1.

Glycoproteomic analysis is always challenging because of low abundance and complex site-specific heterogeneity. Glycoproteins are involved in various biological processes such as cell signaling, adhesion, and cell-cell communication and may serve as potential biomarkers when analyzing different diseases. Here, we investigate glycoproteins in narcolepsy type 1 (NT1) disease, a form of narcolepsy characterized by cataplexy-the sudden onset of muscle paralysis that is typically triggered by intense emotions. In this study, 27 human blood serum samples were analyzed, 16 from NT1 patients and 11 from healthy individuals serving as controls. We quantified hydrophilic interaction liquid chromatography (HILIC)-enriched glycopeptides from low-abundance serum samples of controls and NT1 patients via LC-MS/MS. Twenty-eight unique N-glycopeptides showed significant changes between the two studied groups. The sialylated N-glycopeptide structures LPTQNITFQTESSVAEQEAEFQSPK HexNAc6, Hex3, Neu5Ac2 (derived from the ITIH4 protein) and the structure IVLDPSGSMNIYLVLDGSDSIGASNFTGAK HexNAc5, Hex4, Fuc1 (derived from the CFB protein), with p values of 0.008 and 0.01, respectively, were elevated in NT1 samples compared with controls. In addition, the N-glycopeptide protein sources Ceruloplasmin, Complement factor B, and ITH4 were observed to play an important role in the complement activation and acute-phase response signaling pathways. This may explain the possible association between the biomarkers and pathophysiological effects.