Field Of Bioanalysis Research Articles

Sensitive colorimetric detection of glutathione in human serum based on peroxidase-like activity of chitosan-stabilized gold nanoparticles.

Acolorimetric sensor for the rapid and sensitive detection of GSH was developed. The hydrothermal method was utilized to synthesize chitosan-stabilized gold nanoparticles (CS-AuNPs). The synthesized CS-AuNPs were characterized by UV-vis absorption spectroscopy, transmission electron microscopy (TEM), X-ray diffractograms (XRD), and Fourier transform infrared spectroscopy (FTIR). The CS-AuNPs arewell-dispersed and possess aspherical shapewith an average particle size of 10.05 ± 2.26nm in aqueous solution. Theyshow an intrinsic peroxidase-like activity, which could efficiently catalyze the decomposition of H2O2 to produce •OH radicals. These radicals then oxidized 3, 3´, 5, 5´-tetramethylbenzidine (TMB), resulting in the formation of the blue oxidizedproduct oxTMB, observed a visible color change (from colorless to blue), and oxTMB had an obvious absorption peak at 652nm. The presence of GSH could inhibit the peroxidase-like activity of CS-AuNPs, thereby reducing the formation of oxTMB. The solution's blue hue underwent a reduction in absorption intensity. Based on this fact, a novel and sensitive colorimetric sensor for detection of GSH was constructed. Under optimal conditions, the results of detection had an excellent linear relationship between the concentration of GSH and ∆A within the range 0.5 ~ 50.0 × 10-6mol/L. The limit of detection (LOD) for GSH was 2.10 × 10-7mol/L, which was much lower than those in most previous works. Furthermore, for detection in real human serum samples, the recoveries of GSH and the relative standard deviations (RSD) in the serum were in the range 98.40 ~ 103.32% and 1.85 ~ 3.54%, respectively. Thus, this visual colorimetric method has good precision and can be used for GSH detection in practical applications, promising in the fields of bioanalysis and illness diagnostics.

Paper chip-based colorimetric biosensor for glucose by using CuFe2O4@GO as nanozyme

The development of nanomaterials with notable enzyme-like activity is of great significance to the field of bioanalysis. Herein, a nanomaterial composed of copper ferrite nanoparticles (CuFe2O4 NPs) and graphene oxide (GO) was successfully prepared (CuFe2O4@GO). The obtained CuFe2O4@GO was proved to have peroxidase-like (POD-like) activity, which could catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to generate oxidized TMB (ox-TMB) in the presence of H2O2 with an obvious color change. On this basis, a colorimetric biosensor using a UV–vis spectrometer as readout and a paper chip-based colorimetric biosensor using a smartphone as readout was constructed for glucose detection, respectively, as glucose oxidase (GOD) could oxidize glucose to form H2O2. The UV–vis spectrometer-based approach exhibits a linear range of 0 to 1000 μM and a limit of detection (LOD) of 0.79 μM for glucose. The smartphone-based method shows a linear range of 0.1 to 50 mM and a LOD of 0.04 mM for glucose. Moreover, the fabricated colorimetric biosensors have good selectivity towards glucose and the sample matrixes cannot affect the detection of glucose. Finally, the concentration of glucose in human serum samples was successfully detected using two different ways, and the results are close to the clinical values. The proposed method embraces several good merits. Firstly, the colorimetric biosensors combining UV–vis spectrometer and smartphone offer precise results, which could effectively prevent the occurrence of false events. Secondly, paper-based microfluidic analytical device (μPAD) as analytical platform and smartphone as readout provides a versatile approach for constructing sensitive, cost-effective, and simple colorimetric biosensor for the visual monitoring of glucose. Lastly, except for glucose detection, this work also shows great application prospects for other small molecules detection that could generate H2O2.

Closed Bipolar Nanoelectrode Array for Ultra-Sensitive Detection of Alkaline Phosphatase and Two-Dimensional Imaging of Epidermal Growth Factor Receptors.

The combination of closed bipolar electrodes (cBPE) with electrochemiluminescence (ECL) imaging has demonstrated remarkable capabilities in the field of bioanalysis. Here, we established a cBPE-ECL platform for ultrasensitive detection of alkaline phosphatase (ALP) and two-dimensional imaging of epidermal growth factor receptor (EGFR). This cBPE-ECL system consists of a high-density gold nanowire array in anodic aluminum oxide (AAO) membrane as the cBPE coupled with ECL of highly luminescent cadmium selenide quantum dots (CdSe QDs) luminophores to achieve cathodic electro-optical conversion. When an enzyme-catalyzed amplification effect of ALP with 4-aminophenyl phosphate monosodium salt hydrate (p-APP) as the substrate and 4-aminophenol (p-AP) as the electroactive probe is introduced, a significant improvement of sensing sensitivity with a detection limit as low as 0.5 fM for ALP on the cBPE-ECL platform can be obtained. In addition, the cBPE-ECL sensing system can also be used to detect cancer cells with an impressive detection limit of 50 cells/mL by labeling ALP onto the EGFR protein on A431 human epidermal cancer cell membranes. Thus, two-dimensional (2D) imaging of the EGFR proteins on the cell surface can be achieved, demonstrating that the established cBPE-ECL sensing system is of high resolution for spatiotemporal cell imaging.

Ultrasensitive Paper-Based Photoelectrochemical Biosensor for Acetamiprid Detection Enabled by Spin-State Manipulation and Polarity-Switching.

Efficient carrier separation is vitally crucial to improving the detection sensitivity of photoelectrochemical (PEC) biosensors. Here, we developed a facile strategy to efficiently regulate the carrier separation efficiency of the photoactive matrix BiOI and In2S3 signal label functionalized paper chip by manipulation of electrons spin-state and rational design of electron transport pathways. The spin-dependent electronic structures of BiOI and In2S3 were regulated via enhanced electron-spin parallel alignment induced by an external magnetic field, markedly retarding carrier recombination and extending their lifetime. Simultaneously, with the progress of the target-induced catalytic hairpin assembly process, the transfer path of photogenerated carriers was changed, leading to a switch in photocurrent polarity from cathode to anode. This reversed electron transport pathway not only boosted the separation ability of photogenerated electrons but also eliminated false-positive and false-negative signals, thereby further improving the detection sensitivity. As a proof of concept, the well-designed magnetic field-stimulated paper-based PEC biosensor showed highly selectivity and sensitivity for acetamiprid assay with a wide linear range of 1 fM to 20 nM and an ultralow detection limit of 0.73 fM. This work develops a universal strategy for improving the sensitivity of biosensors and exhibits enormous potential in the fields of bioanalysis and clinical diagnosis.

Atypical applications of transverse diffusion of laminar flow profiles methodology for in-capillary reactions in capillary electrophoresis.

Capillary electrophoresis (CE) is a powerful separation technique offering quick and efficient analyses in various fields of bioanalytical chemistry. It is characterized by many well-known advantages, but one, which is perhaps the most important for this application field, is somewhat overlooked. It is the possibility to perform chemical and biochemical reactions at the nL scale inside the separation capillary. There are two basic formats applicable for this purpose, heterogeneous and homogeneous. In the former, one reactant is immobilized onto a particle or monolithic support or directly on the capillary wall, and the other is injected. In the latter, the reactant mixing inside a capillary is based on electromigration or diffusion. One of the diffusion-based methodologies, termed Transverse Diffusion of Laminar Flow Profiles, is the subject of this review. Since most studies utilizing in-capillary reactions in CE focus on enzymes, which are being continuously and exhaustively reviewed, this review covers the atypical applications of this methodology, but still in the bioanalytical field. As can be seen from the demonstrated applications, they are not limited to reactions, but can also be utilized for other biochemical systems.

Development of quantitative detection methods for four Alzheimer's disease specific biomarker panels using electrochemical immunosensors based on enzyme immunoassay.

Accurate and timely diagnosis of Alzheimer's disease (AD) is necessary to maximize the effectiveness of treatment and using biomarkers for diagnosis is attracting attention as a minimally invasive method with few side effects. Electrochemical immunosensor (EI) is a method that is in the spotlight in the medical and bioanalytical fields due to its portability and field usability. Here, we quantified four AD specific biomarkers using EIs based on enzyme immunoassay. We selected and developed quantitative methods for the biomarkers using screen-printed gold electrodes. For three biomarkers, quantification was performed using competition immunoassays in which antigen-antibody premix mixtures were applied to antigen-immobilized electrodes and the limit of detection (LOD) values were secured, 1.20 ng/ml, 1.30 ng/ml, and 1.74 ng/ml, respectively. For the other, a sandwich immunoassay using antibody pair was selected for quantification and LOD was also achieved as 0.077 ng/ml. All four biomarkers in buffer samples were successfully quantified and reliable R2 values were obtained, and reliable calibration curves were secured for three biomarkers in spiked human serum samples. The immunosensors developed and will be optimized are expected to be used in various fields, including detection of biomarkers for not only AD but also related diseases.

Combining PDMS Composite and Plasmonic Solid Chemosensors: Dual Determination of Ammonium and Hydrogen Sulfide as Biomarkers in a Saliva Single Test

In recent years, in the field of bioanalysis, the use of saliva as a biological fluid for the determination of biomarkers has been proposed. Saliva analysis stands out for its simplicity and non-invasive sampling. This paper proposes a method for the dual determination of ammonium and hydrogen sulfur in saliva using two colorimetric chemosensors. The ammonia reacts with 1,2-Naftoquinone 4 sulphonic acid (NQS) entrapped in polydimethylsiloxane (PDMS) and the hydrogen sulfide with AgNPs retained in a nylon membrane. The color changed from orange to brown in the case of ammonia chemosensors and from yellow to brown in the H2S. The experimental conditions to be tested have been established. Both analytes have been determined from their gaseous form; these are ammonia from ammonium and hydrogen sulfur from hydrogen sulfur. Good figures of merit have been obtained by using both measuring strategies (reflectance diffuse and digitalized images). The acquired results show that both sensors can be used and provide good selectivity and sensitivity for the determination of these biomarkers in saliva. Both measurement strategies have provided satisfactory results for the real saliva samples (n = 15). Recoveries on spiked samples were between 70 and 100%. This methodology can lead to possible in situ diagnosis and monitoring of certain diseases and pathologies related with NH4+ and/or H2S, in a fast, simple, cheap and non-invasive way.

Upgraded and Light-Up Biosensing Platform: Entropy-Driven Catalysis Circuit Manipulates the Configuration Transformation of Novel DNA Silver Nanoclusters on the Graphene Oxide Surface.

To tackle the predicament of the traditional turn-off mechanism, exploring an activated turn-on system remains an intriguing and crucial objective in biosensing fields. Herein, a dark DNA Ag nanocluster (NC) with hairpin-structured DNA containing a six-base cytosine loop (6C loop) as a template is atypically synthesized. Intriguingly, the dark DNA Ag NCs can be lit to display strong red-emission nanoclusters. Building upon these exciting findings, an unprecedented and upgraded turn-on biosensing system [entropy-driven catalysis circuit (EDCC)-Ag NCs/graphene oxide (GO)] has been created, which employs an EDCC to precisely manipulate the conformational transition of DNA Ag NCs on the GO surface from adsorption to desorption. Benefiting from the effective quenching of GO and signal amplification capability of the EDCC, the newly developed EDCC-Ag NCs/GO biosensing system displays a high signal-to-background (S/B) ratio (26-fold) and sensitivity (limit of detection as low as 0.4 pM). Meanwhile, it has good specificity, excellent stability, and reliability in both buffer and biological samples. To the best of our knowledge, it is the first example that adopts an EDCC to precisely modulate the configuration transformation of DNA Ag NCs on the GO surface to obtain a biosensor with low background, strong fluorescence, high contrast, and sensitivity. This exciting finding may provide a new route to fabricate a novel turn-on biosensor based on hairpin-templated DNA Ag NCs in the optical imaging and bioanalytical fields.

Multifunctional Supramolecular Hydrogel Modulated Heterojunction Interface Carrier Transport Engineering Facilitates Sensitive Photoelectrochemical Immunosensing.

Highly responsive interface of semiconductor nanophotoelectrochemical materials provides a broad development prospect for the identification of low-abundance cancer marker molecules. This work innovatively proposes an efficient blank WO3/SnIn4S8 heterojunction interface formed by self-assembly on the working electrode for interface regulation and photoregulation. Different from the traditional biomolecular layered interface, a hydrogel layer containing manganese dioxide with a wide light absorption range is formed at the interface after an accurate response to external immune recognition. The formation of the hydrogel layer hinders the effective contact between the heterojunction interface and the electrolyte solution, and manganese dioxide in the hydrogel layer forms a strong competition between the light source and the substrate photoelectric material. The process effectively improves the carrier recombination efficiency at the interface, reduces the interface reaction kinetics and photoelectric conversion efficiency, and thus provides strong support for target identification. Taking advantage of the process, the resulting biosensors are being explored for sensitive detection of human epidermal growth factor receptor 2, with a limit of detection as low as 0.037 pg/mL. Also, this study contributes to the advancement of photoelectrochemical biosensing technology and opens up new avenues for the development of sensitive and accurate analytical tools in the field of bioanalysis.

Fe-single-atom catalysts boosting electrochemiluminescence via bipolar electrode integrated with its peroxidase-like activity for bioanalysis

Multifunctional single-atom catalysts (SACs) have been extensively investigated as outstanding signal amplifiers in bioanalysis field. Herein, a type of Fe single-atom catalysts with Fe-nitrogen coordination sites in nitrogen-doped carbon (Fe–N/C SACs) was synthesized and demonstrated to possess both catalase and peroxidase-like activity. Utilizing Fe–N/C SACs as dual signal amplifier, an efficient bipolar electrode (BPE)-based electrochemiluminescence (ECL) immunoassay was presented for determination of prostate-specific antigen (PSA). The cathode pole of the BPE-ECL platform modified with Fe–N/C SACs is served as the sensing side and luminol at the anode as signal output side. Fe–N/C SACs could catalyze decomposition of H2O2 via their high catalase-like activity and then increase the Faraday current, which can boost the ECL of luminol due to the electroneutrality in a closed BPE system. Meanwhile, in the presence of the target, glucose oxidase (GOx)-Au NPs-Ab2 was introduced through specific immunoreaction, which catalyzes the formation of H2O2. Subsequently, Fe–N/C SACs with peroxidase-like activity catalyze the reaction of H2O2 and 4-chloro-1-naphthol (4-CN) to generate insoluble precipitates, which hinders electron transfer and then inhibits the ECL at the anode. Thus, dual signal amplification of Fe–N/C SACs was achieved by increasing the initial ECL and inhibiting the ECL in the presence of target. The assay exhibits sensitive detection of PSA linearly from 1.0 pg/mL to 100 ng/mL with a detection limit of 0.62 pg/mL. The work demonstrated a new ECL enhancement strategy of SACs via BPE system and expands the application of SACs in bioanalysis field.

Multimode sensing and imaging platform for versatile detection of GSH based on surface modification strategy of Ru(bpy)32+ doped SiO2 nanoparticles

A multimode sensing and imaging platform based on surface modification strategy of Ru(bpy)32+ doped SiO2 nanoparticles (RuSiO2 NPs) was constructed for versatile detection of glutathione (GSH). RuSiO2 NPs as the luminophore models had outstanding fluorescence (FL) and electrochemiluminescence (ECL) signals. Furthermore, its FL signal could be captured by electrophoresis analyzer, and the ECL signal could be imaged with mobile phone to achieve visualization. So, a unique and convenient multi-mode sensing and imaging platform could be developed based on RuSiO2 NPs. SiO2 NPs could realize enrichment of Ru(bpy)32+ based on the nanoconfined effect to achieve signal amplification, and its surface was rich with abundant hydroxyl functional groups, which offered a channel for surface modification. Sulfhydryl modification on the RuSiO2 NPs was realized by using silane coupling agent, and KMnO4 was used to in situ generate MnO2 shell on the surface of RuSiO2 NPs for quenching its ECL, FL, and colorimetric (CL) signals based on resonance energy transfer (RET). Target GSH could reduce MnO2 shell to realize recovery of all signals, thus achieving the label-free multimode detection of GSH. Therefore, this work developed a multimode sensing and imaging platform without signal labels or layer-by-layer assembly of electrodes, which had the advantages of simple steps, low cost, and high detection accuracy, showing important application potential in the field of bioanalysis.

Design and analysis of hetero-dielectric Junctionless-TFET(JL-TFET) with N+ pocket as label free biosensors

This paper includes sensitivity assessment of label-free biosensors using hetero dielectric Junctionless-TFET (HD-JL-TFET) thorough TCAD simulator. The fundamental structure, operation and design of a Junctionless-TFET (HD-JL-TFET) as biosensor are investigated in this paper. For the purpose of detecting the biomolecule, a nano-gap is added close to the source end between the gate and channel. To test the sensing potential, we adjusted the charge density and material dielectric constant (K) by comprehensive calibrated device simulation. For several biomolecules, the device’s sensitivity was examined as surface potential, electron tunnelling rate, and conduction-valence band edge fluctuation. Additionally, the Id versus VGS features, the sensitivity to the drain current, and the ION/IOFF fluctuation are also examined. By contrasting neutral or charged biomolecules using various dielectric constants, the sensitivity characteristics of positive, negative, and neutral biomolecules are examined. The development of biosensors, which enable the rapid and precise detection of multiple biomolecules, has revolutionized the field of bioanalysis.

Ratiometric fluorometric assay triggered by alkaline phosphatase: Proof-of-concept toward a split-type biosensing strategy for DNA detection

Herein, a sensitive ratiometric and split-type fluorescent sensing platform has been constructed for DNA detection based on one signal precursor and two fluorescent signal indicators. In this assay, o-phenylenediamine (OPD) was selected as the signal precursor. On one hand, Cu2+ can oxidize OPD to produce 2, 3-diaminophenazine (DAP), which with an emission peak at 555 nm. On the other hand, ascorbic acid (AA) could react with Cu2+ to generate dehydroascorbic acid (DHAA), which could further react with OPD to form 3-(1, 2-dihydroxy ethyl)furo[3, 4-b]quinoxalin-1 (3H)-on (DFQ) with a strong emission peak at 420 nm. As a result, the formation of DAP was inhibited, and leading to the decrease of fluorescence intensity at 555 nm. Alkaline phosphatase (ALP) could catalyze the substrate l-ascorbic acid-2-phosphate (AA2P) to produce AA in situ. Inspired by the successful use of ALP as a biocatalytic marker in bioassay, a split-type ratiometric fluorescent assay has been designed for DNA detection by using H1N1 DNA as the target model. It was realized for ratiometric fluorescent determination of H1N1 in a linear ranging from 50 pM to 1.5 nM with a limit of detection of 10 pM. The novel strategy could reduce the mutual interferences between the biomolecular recognition system and the fluorescence signal conversion system, which improving the accuracy of detection and effectively reducing the background signal. Furthermore, the strategy provided a promising platform for biomarkers detection in the fields of ratiometric fluorescent biosensors and bioanalysis.

Peptide aptamer-based colorimetric sensor for the detection of L-tryptophan in porcine serum

L-Tryptophan (L-Trp), one of the essential amino acids, is crucial for human physiological homeostasis and a limiting amino acid in animal feed. In addition, L-Trp is a precursor of some important biomolecules in the body, such as pentraxin and melatonin. Disorders of L-Trp metabolism in the body may cause Alzheimer's or Parkinson's disease. Therefore, monitoring L-Trp levels in the body fluids quickly and accurately is essential. A colorimetric biosensor was developed for the rapid detection of L-Trp in solutions by coupling a novel, screened, and validated peptide aptamer with Au nanoparticles via the Au-S bond. The biosensor showed a wide linear detection range of 1 µM − 1000 µM, and in addition, it was simple to construct, and the reaction time was as short as 10 s. In the analysis of L-Trp in actual porcine serum samples, the relative standard deviations were 4.52 % to 3.01 % compared with those of the high-performance liquid chromatography method, and the spiked recoveries were 99.2 % to 100.2 %. This new type of recognition probe is likely to gain attention in the field of bioanalysis owing to its biocompatibility, ease of modification, and easy linkage to nanomaterials.

2-Aminopurine-based quencher-free DNA tweezers with fluorescence properties well tuned by surrounding bases.

Reversible structural changes in DNA nanomachines have great potential in the field of bioanalysis. Here, we demonstrate an assembly strategy for quencher-free and tunable DNA tweezers based on 2-aminopurine (2-AP), avoiding the tedious fluorescence labelling step. The conformational state of the tweezers could be controlled by specific oligonucleotides (fuel or anti-fuel). Taking advantage of the local environmental sensitivity of 2-AP, the structural changes of the tweezers were easily tracked, and multiple cyclic switching of the tweezers between the open and closed states was achieved. In addition, the influence of oligonucleotide structure on the fluorescence properties of 2-AP was deeply explored. We figured out that the fluorescence of 2-AP was highly quenched by the base-stacking of natural bases in DNA oligonucleotides. Moreover, by comprehensively regulating the type of bases surrounding the inserted 2-AP site, a sensitive fluorescence response towards dynamic change can be obtained. This principle of quencher-free nanodevices based on 2-AP provides a convenient method for monitoring the structural changes of DNA nanomachines.

Advances in rapid point-of-care virus testing.

Outbreaks of viral diseases seriously jeopardize people's health and cause huge economic losses. At the same time, virology provides a new perspective for biology, molecular biology and cancer research, and it is important to study the discovered viruses with potential applications. Therefore, the development of immediate and rapid viral detection methods for the prevention and treatment of viral diseases as well as the study of viruses has attracted extensive attention from scientists. With the continuous progress of science and technology, especially in the field of bioanalysis, a series of new detection techniques have been applied to the on-site rapid detection of viruses, which has become a powerful approach for human beings to fight against viruses. In this paper, the latest research progress of rapid point-of-care detection of viral nucleic acids, antigens and antibodies is presented. In addition, the advantages and disadvantages of these technologies are discussed from the perspective of practical application requirements. Finally, the problems and challenges faced by rapid viral detection methods and their development prospects are discussed.

Real time NIR detection of biogenic amine using an Yb4L4 tetrahedron

Fluorescent sensors of biogenic amines (BAs) due to their excitation or emission in the UV–Vis region, which limits its application in the field of bioanalysis. Herein, an Yb(III) tetrahedral Yb4L34 with ILCT characteristic was constructed from a tris-β-diketone ligand, its spin-coated film shows high sensitivity and fast reversible responses to some BAs with the ppm level detection limit and millisecond response time in NIR region. Compared with Yb4L24, the response time of Yb4L34 was effectively reduced by enlarge the cavity volume and rhombus opening lying on the edges of cage, this indicates that the porosity of film was further enhanced and the interaction time (between Yb4L34 and BAs) was decreased. Moreover, the response time of Yb4L34 was faster than that of most fluorescent amine sensors. In addition, the emission of Yb4L34 in NIR region shows significantly quenching after exposure to the vapor of spoiled fish in 89 ms, which implies that Yb4L34 could be used to real time monitor freshness of food.

Design of a dual Ir-Eu tag for fluorescent visualization and ICP-MS quantification of SIRPα and its host cells.

With the expansion of ICP-MS application into the field of bioanalysis, there is an urgent need for novel element tags today. Here, we report the design of a dual-element Ir-Eu tag, opening the door to simultaneous fluorescent imaging and ICP-MS quantification. The ratio of 153Eu/193Ir may serve as a precision control of the labeling process, allowing internal validation of the quantitative results obtained. As for SIRPα and its host cell analysis exemplified here, the Ir-Eu tag demonstrated superior figures of ICP-MS quantification with the LOD (3σ) down to 0.5 (153Eu) and 1.1 (193Ir) pM SIRPα and 220 (153Eu) and 830 (193Ir) RAW264.7 cells more than 130 times more sensitive compared with the LOD (3σ) of 65.2 pM SIRPα at 612 nm using fluorometry. Not limited to these demonstrations, we believe that the design ideas of the dual Ir-Eu tags should be applicable to various cases of bioanalysis when dual optical profiling and ICP-MS quantification are indispensable.

Low-Cost Plant-Based Metal and Metal Oxide Nanoparticle Synthesis and Their Use in Optical and Electrochemical (Bio)Sensors.

Technological progress has led to the development of analytical tools that promise a huge socio-economic impact on our daily lives and an improved quality of life for all. The use of plant extract synthesized nanoparticles in the development and fabrication of optical or electrochemical (bio)sensors presents major advantages. Besides their low-cost fabrication and scalability, these nanoparticles may have a dual role, serving as a transducer component and as a recognition element, the latter requiring their functionalization with specific components. Different approaches, such as surface modification techniques to facilitate precise biomolecule attachment, thereby augmenting recognition capabilities, or fine tuning functional groups on nanoparticle surfaces are preferred for ensuring stable biomolecule conjugation while preserving bioactivity. Size optimization, maximizing surface area, and tailored nanoparticle shapes increase the potential for robust interactions and enhance the transduction. This article specifically aims to illustrate the adaptability and effectiveness of these biosensing platforms in identifying precise biological targets along with their far-reaching implications across various domains, spanning healthcare diagnostics, environmental monitoring, and diverse bioanalytical fields. By exploring these applications, the article highlights the significance of prioritizing the use of natural resources for nanoparticle synthesis. This emphasis aligns with the worldwide goal of envisioning sustainable and customized biosensing solutions, emphasizing heightened sensitivity and selectivity.

A simple and green capillary electrophoresis-mass spectrometry method for therapeutic drug monitoring of colistin in clinical plasma samples

Colistin and other polymyxin antibiotics have become increasingly used in clinical settings as a result of treating multidrug-resistant infections in critically ill patients. The highly variable pharmacokinetics of colistin in these patients is accompanied by a high risk of toxicity or underdosing. An effective tool that allows rational optimization of the drug dosage regimen is therapeutic drug monitoring. Therefore, there is a need to dispose with appropriate, sensitive, and accurate analytical methods. Here, a simple, specific, and accurate on-line capillary electrophoresis – tandem mass spectrometry method was developed and applied for the first time to determine colistin in human plasma. Protein precipitation using acidified acetonitrile was the solitary procedure used to achieve sample pretreatment. A bare fused silica capillary was employed for the separation process, and the background electrolyte used was 50 mM formic acid (pH 2.54). The FDA's bioanalytical method validation guidelines were followed in the validation of the proposed method. For colistin A and colistin B, favorable performance and validation parameters were obtained (such as linearity, limit of detection, lower limit of quantitation, intra-day and inter-day precision, accuracy, and stability).The validated method was then effectively used to analyze real clinical samples taken from patients who were in critical condition. Our newly developed method is comparable with previously published liquid chromatography approaches and has the potential to be applied in the therapeutic monitoring of colistin in routine clinical laboratories. Moreover, according to the greenness assessment, the developed capillary electrophoresis – mass spectrometry method represents a very interesting green and sustainable tool in the field of bioanalysis.