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1.
J Nanobiotechnology ; 22(1): 414, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39010059

ABSTRACT

Staphylococcus aureus (SA) poses a serious risk to human and animal health, necessitating a low-cost and high-performance analytical platform for point-of-care diagnostics. Cellulose paper-based field-effect transistors (FETs) with RNA-cleaving DNAzymes (RCDs) can fulfill the low-cost requirements, however, its high hydrophilicity and lipophilicity hinder biochemical modification and result in low sensitivity, poor mechanical stability and poor fouling performance. Herein, we proposed a controllable self-cleaning FET to simplify biochemical modification and improve mechanical stability and antifouling performance. Then, we constructed an RCD-based DNA nanotree to significantly enhance the sensitivity for SA detection. For controllable self-cleaning FET, 1 H,1 H,2 H,2 H-perfluorodecyltrimethoxysilane based-polymeric nanoparticles were synthesized to decorate cellulose paper and whole carbon nanofilm wires. O2 plasma was applied to regulate to reduce fluorocarbon chain density, and then control the hydrophobic-oleophobic property in sensitive areas. Because negatively charged DNA affected the sensitivity of semiconducting FETs, three Y-shaped branches with low-cost were designed and applied to synthesize an RCD-based DNA-Nanotree based on similar DNA-origami technology, which further improved the sensitivity. The trunk of DNA-Nanotree was composed of RCD, and the canopy was self-assembled using multiple Y-shaped branches. The controllable self-cleaning FET biosensor was applied for SA detection without cultivation, which had a wide linear range from 1 to 105 CFU/mL and could detect a low value of 1 CFU/mL.


Subject(s)
Biosensing Techniques , DNA, Catalytic , Staphylococcus aureus , DNA, Catalytic/chemistry , DNA, Catalytic/metabolism , Biosensing Techniques/methods , Transistors, Electronic , RNA/metabolism , Limit of Detection , Cellulose/chemistry , Paper , Nanoparticles/chemistry , Humans
2.
Cell Rep Methods ; 4(7): 100821, 2024 Jul 15.
Article in English | MEDLINE | ID: mdl-39013362

ABSTRACT

Molecular tension sensors are central tools for mechanobiology studies but have limitations in interpretation. Reporting in Cell Reports Methods, Shoyer et al. discover that fluorescent protein photoswitching in concert with sensor extension may expand the use and interpretation of common force-sensing tools.


Subject(s)
Biosensing Techniques , Biosensing Techniques/methods , Biosensing Techniques/instrumentation
3.
ACS Appl Mater Interfaces ; 16(28): 36194-36203, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38952261

ABSTRACT

The occurrence of cancer is often closely related to multiple tumor markers, so it is important to develop multitarget detection methods. By the proper design of the input signals and logical operations of DNA logic gates, detection and diagnosis of cancer at different stages can be achieved. For example, in the early stages, specific input signals can be designed to correspond to early specific tumor markers, thereby achieving early cancer detection. In the late stage, logic gates for multitarget detection can be designed to simultaneously detect multiple biomarkers to improve diagnostic accuracy and comprehensiveness. In this work, we constructed a dual-target-triggered DNA logic gate for anchoring DNA tetrahedra, where methylene blue was embedded in the DNA tetrahedra to sensitize ZnO@CdS@Au, achieving ultrasensitive detection of the target substance. We tested the response of AND and OR logic gates to the platform. For AND logic gates, the sensing platform only responds when both miRNAs are present. In the concentration range of 10 aM to 10 nM, the photoelectric signal gradually increases with an increase of the target concentration. Subsequently, we used OR logic gates for miRNA detection. Even if only one target exists, the sensing platform exhibits excellent performance. Similarly, within the concentration range of 10 aM to 10 nM, the photoelectric signal gradually increases with an increase of the target concentration. The minimum detection limit is 1.10 aM. Whether it is the need to detect multiple targets simultaneously or only one of them, we can achieve it by selecting the appropriate logic gate. This strategy holds promising application prospects in fields such as biosensing, medical diagnosis, and environmental monitoring.


Subject(s)
Biosensing Techniques , Cadmium Compounds , Electrochemical Techniques , Gold , Methylene Blue , MicroRNAs , Nanotubes , Sulfides , Zinc Oxide , Methylene Blue/chemistry , Zinc Oxide/chemistry , Biosensing Techniques/methods , Gold/chemistry , Nanotubes/chemistry , Cadmium Compounds/chemistry , Electrochemical Techniques/methods , MicroRNAs/analysis , Sulfides/chemistry , Humans , Limit of Detection , Logic
4.
ACS Appl Mater Interfaces ; 16(28): 36106-36116, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38955781

ABSTRACT

Accurate detection of heterogeneous circulating tumor cells (CTCs) is critical as they can make tumor cells more aggressive, drug-resistant, and metastasizing. Although the leukocyte membrane coating strategy is promising in meeting the challenge of detecting heterogeneous CTCs due to its inherent antiadhesive properties, it is still limited by the reduction or loss of expression of known markers. Bioorthogonal glycol-metabolic engineering is expected to break down this barrier by feeding the cells with sugar derivatives with a unique functional group to establish artificial targets on the surface of tumor cells. Herein, an engineered leukocyte biomimetic colorimetric sensor was accordingly fabricated for high-efficient detection of heterogeneous CTCs. Compared with conventional leukocyte membrane coating, the sensor could covalently bound to the heterogeneous CTCs models fed with Ac4ManNAz in vitro through the synergy of bioorthogonal chemistry and metabolic glycoengineering, ignoring the phenotypic changes of heterogeneous CTCs. Meanwhile, a sandwich structure composed of leukocyte biomimetic layer/CTCs/MoS2 nanosheet was formed for visual detection of HeLa cells as low as 10 cells mL-1. Overall, this approach can overcome the dependence of conventional cell membrane biomimetic technology on specific cell phenotypes and provide a new viewpoint to highly efficiently detect heterogeneous CTCs.


Subject(s)
Biomimetic Materials , Colorimetry , Leukocytes , Neoplastic Cells, Circulating , Humans , Colorimetry/methods , HeLa Cells , Neoplastic Cells, Circulating/pathology , Neoplastic Cells, Circulating/metabolism , Leukocytes/cytology , Leukocytes/metabolism , Biomimetic Materials/chemistry , Biomimetics/methods , Biosensing Techniques/methods
5.
ACS Appl Mater Interfaces ; 16(28): 37087-37099, 2024 Jul 17.
Article in English | MEDLINE | ID: mdl-38958653

ABSTRACT

Hydrogels, as flexible materials, have been widely used in the field of flexible sensors. Human sweat contains a variety of biomarkers that can reflect the physiological state of the human body. Therefore, it is of great practical significance and application value to realize the detection of sweat composition and combine it with human motion sensing through a hydrogel. Based on mussel-inspired chemistry, polydopamine (PDA) and gold nanoparticles (AuNPs) were coated on the surface of cellulose nanocrystals (CNCs) to obtain CNC-based nanocomposites (CNCs@PDA-Au), which could simultaneously enhance the mechanical, electrochemical, and self-healing properties of hydrogels. The CNCs@PDA-Au was composited with poly(vinyl alcohol) (PVA) hydrogel to obtain the nanocomposite hydrogel (PVA/CNCs@PDA-Au) by freeze-thaw cycles. The PVA/CNCs@PDA-Au has excellent mechanical strength (7.2 MPa) and self-healing properties (88.3%). The motion sensors designed with PVA/CNCs@PDA-Au exhibited a fast response time (122.9 ms), wide strain sensing range (0-600.0%), excellent stability, and fatigue resistance. With the unique electrochemical redox properties of uric acid, the designed hydrogel sensor successfully realized the detection of uric acid in sweat with a wide detection range (1.0-100.0 µmol/L) and low detection limit (0.42 µmol/L). In this study, the dual detection of human motion and uric acid in sweat was successfully realized by the designed PVA/CNCs@PDA-Au nanocomposite hydrogel.


Subject(s)
Cellulose , Gold , Hydrogels , Nanocomposites , Polymers , Sweat , Cellulose/chemistry , Nanocomposites/chemistry , Humans , Hydrogels/chemistry , Gold/chemistry , Sweat/chemistry , Polymers/chemistry , Metal Nanoparticles/chemistry , Polyvinyl Alcohol/chemistry , Nanoparticles/chemistry , Indoles/chemistry , Biosensing Techniques/methods , Electrochemical Techniques/methods , Limit of Detection , Motion
6.
J Mol Model ; 30(8): 256, 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38972935

ABSTRACT

CONTEXT: Iridoviruses, a group of double-stranded DNA viruses, pose a significant threat to various aquatic animals, causing substantial economic losses in aquaculture and impacting ecosystem health. Early and accurate detection of these viruses is crucial for effective disease management and control. Conventional diagnostic methods, including polymerase chain reaction (PCR) and virus isolation, often require specialized laboratories, skilled personnel, and considerable time. This highlights the need for rapid, sensitive, and cost-effective diagnostic tools for iridovirus detection. Single-layer graphene, a two-dimensional material with unique properties like high surface area, excellent electrical conductivity, and chemical stability, has emerged as a versatile platform for biosensing applications. This paper explores the potential of employing single-layer graphene in the development of a bionanosensor for the sensitive and rapid detection of iridoviruses. The aim of the present investigation is to develop a sensor by analyzing the vibrational responses of single-layer graphene sheets (SLGS) with attached microorganisms. Graphene-based virus sensors typically rely on the interaction between the virus and the graphene surface, which lead to changes in the frequency response of graphene. This change is measured and used to detect the presence of the virus. Its high surface-to-volume ratio and sensitivity to changes in its frequency make it a highly sensitive platform for virus detection. METHODS: We employ finite element method (FEM) analysis to model the sensor's performance and optimize its design parameters. The simulation results highlight the sensor's potential for achieving high sensitivity and rapid detection of iridovirus. Bridged and simply supported with roller support boundary conditions applied at the ends of SLG structure. Simulations have been performed to see how SLG behaves when used as sensors. A single-layer graphene armchair SLG (5,5) with 50-nm length exhibits its highest frequency vibration at 8.66 × 106 Hz, with a mass of 1.2786 Zg. In contrast, a zigzag-SLG with a (18,0) configuration has its lowest frequency vibration at 2.82 × 105 Hz. This aids in comprehending the thresholds of detection and the influence of factors such as size, and boundary conditions on sensor effectiveness. These biosensors can be especially helpful in biological sciences and the medical field since they can considerably improve the treatment of patients, cancer early diagnosis, and pathogen identification when used in clinical environments.


Subject(s)
Biosensing Techniques , Graphite , Iridovirus , Graphite/chemistry , Biosensing Techniques/methods
7.
Mikrochim Acta ; 191(8): 448, 2024 07 05.
Article in English | MEDLINE | ID: mdl-38967796

ABSTRACT

Surface functionalization strategy is becoming a crucial bridge from magnetic nanoparticles (MNPs) to their broad bio-application. To realize the multiple functions of MNPs such as magnetic manipulation, target capture, and signal amplification in their use of electrochemical biosensing, co-crosslinking strategy was proposed here to construct dual-functionalized MNPs by combining ultra-sensitive redox moieties and specific biological probes. In this work, MNPs with a TEM size of 10 nm were synthesized by co-precipitation for amination and PEGylation to maintain colloid stability once dispersed in high-ionic-strength buffer (such as phosphate-buffered saline). Then, MNPs@IgG were prepared via the bis(sulfosuccinimidyl) suberate (BS3) cross-linker to conjugate these IgG onto the MNP surface, with a binding efficiency of 73%. To construct dual-functionalized MNPs, these redox probes of ferrocene-NHS (Fc) were co-crosslinked onto the MNP surface, together with IgG, by using BS3. The developed MNPs@Redox@IgG were characterized by SDS‒PAGE to identify IgG binding and by square wave voltammetry (SWV) to validate the redox signal. Additionally, the anti-CD63 antibodies were selected for the development of MNPs@anti-CD63 for use in the bio-testing of exosome sample capture. Therefore, co-crosslinking strategy paved a way to develop dual-functionalized MNPs that can be an aid of their potential utilization in diagnostic assay or electrochemical methods.


Subject(s)
Cross-Linking Reagents , Immunoglobulin G , Magnetite Nanoparticles , Oxidation-Reduction , Magnetite Nanoparticles/chemistry , Immunoglobulin G/chemistry , Humans , Cross-Linking Reagents/chemistry , Ferrous Compounds/chemistry , Metallocenes/chemistry , Biosensing Techniques/methods , Tetraspanin 30/immunology , Electrochemical Techniques/methods
8.
World J Microbiol Biotechnol ; 40(9): 269, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-39009934

ABSTRACT

Gold Nanoparticles (AuNPs) have gained significant attention in biosensor development due to their unique physical, chemical, and optical properties. When incorporated into biosensors, AuNPs offer several advantages, including a high surface area-to-volume ratio, excellent biocompatibility, ease of functionalization, and tunable optical properties. These properties make them ideal for the detection of various biomolecules, including proteins, nucleic acids, and bacterial and viral biomarkers. Traditional methods for detecting bacteria and viruses, such as RT-PCR and ELISA, often suffer from complexities, time consumption, and labor intensiveness. Consequently, researchers are continuously exploring novel devices to address these limitations and effectively detect a diverse array of infectious pathogenic microorganisms. In light of these challenges, nanotechnology has been instrumental in refining the architecture and performance of biosensors. By leveraging advancements in nanomaterials and strategies of biosensor fabrication the sensitivity and specificity of biosensors can be enhanced, enabling more precise detection of pathogenic bacteria and viruses. This review explores the versatility of AuNPs in detecting a variety of biomolecules, including proteins, nucleic acids, and bacterial and viral biomarkers. Furthermore, it evaluates recent advancements in AuNPs-based biosensors for the detection of pathogens, utilizing techniques such as optical biosensors, lateral flow immunoassays, colorimetric immunosensors, electrochemical biosensors, and fluorescence nanobiosensors. Additionally, the study discusses the existing challenges in the field and proposes future directions to improve AuNPs-based biosensors, with a focus on enhancing sensitivity, selectivity, and their utility in clinical and diagnostic applications.


Subject(s)
Bacteria , Biosensing Techniques , Gold , Metal Nanoparticles , Viruses , Biosensing Techniques/methods , Gold/chemistry , Metal Nanoparticles/chemistry , Viruses/isolation & purification , Bacteria/isolation & purification , Nanotechnology/methods , Humans , Biomarkers/analysis , Virus Diseases/diagnosis , Immunoassay/methods
9.
Sensors (Basel) ; 24(13)2024 Jun 23.
Article in English | MEDLINE | ID: mdl-39000857

ABSTRACT

Tactile texture sensors are designed to evaluate the sensations felt when a human touches an object. Prior studies have demonstrated the necessity for these sensors to have compliant ridges on their surfaces that mimic human fingerprints. These features enable the simulation of contact phenomena, especially friction and vibration, between human fingertips and objects, enhancing the tactile sensation evaluation. However, the ridges on tactile sensors are susceptible to abrasion damage from repeated use. To date, the healing function of abraded ridges has not been proposed, and its effectiveness needs to be demonstrated. In this study, we investigated whether the signal detection capabilities of a sensor with abraded epidermal ridges could be restored by healing the ridges using polyvinyl chloride plastisol as the sensor material. We developed a prototype tactile sensor with an embedded strain gauge, which was used to repeatedly scan roughness specimens. After more than 1000 measurements, we observed significant deterioration in the sensor's output signal level. The ridges were then reshaped using a mold with a heating function, allowing the sensor to partially regain its original signal levels. This method shows potential for extending the operational lifespan of tactile texture sensors with compliant ridges.


Subject(s)
Dermatoglyphics , Touch , Humans , Touch/physiology , Fingers/physiology , Surface Properties , Biosensing Techniques/methods , Biosensing Techniques/instrumentation
10.
Sensors (Basel) ; 24(13)2024 Jun 27.
Article in English | MEDLINE | ID: mdl-39000945

ABSTRACT

Exploring the objective signals associated with subjective emotional states has practical significance [...].


Subject(s)
Emotions , Emotions/physiology , Humans , Biosensing Techniques/methods
11.
Sensors (Basel) ; 24(13)2024 Jun 30.
Article in English | MEDLINE | ID: mdl-39001045

ABSTRACT

Nucleic acid tests are key tools for the detection and diagnosis of many diseases. In many cases, the amplification of the nucleic acids is required to reach a detectable level. To make nucleic acid amplification tests more accessible to a point-of-care (POC) setting, isothermal amplification can be performed with a simple heating source. Although these tests are being performed in bulk reactions, the quantification is not as accurate as it would be with digital amplification. Here, we introduce the use of the vibrating sharp-tip capillary for a simple and portable system for tunable on-demand droplet generation. Because of the large range of droplet sizes possible and the tunability of the vibrating sharp-tip capillary, a high dynamic range (~2 to 6000 copies/µL) digital droplet loop-mediated isothermal amplification (ddLAMP) system has been developed. It was also noted that by changing the type of capillary on the vibrating sharp-tip capillary, the same mechanism can be used for simple and portable DNA fragmentation. With the incorporation of these elements, the present work paves the way for achieving digital nucleic acid tests in a POC setting with limited resources.


Subject(s)
Nucleic Acid Amplification Techniques , Nucleic Acid Amplification Techniques/methods , Nucleic Acid Amplification Techniques/instrumentation , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Vibration , Point-of-Care Systems , Humans , Nucleic Acids/analysis , DNA/analysis , DNA/genetics , DNA/chemistry
12.
Sensors (Basel) ; 24(13)2024 Jun 30.
Article in English | MEDLINE | ID: mdl-39001043

ABSTRACT

The properties of nanopipettes largely rely on the materials introduced onto their inner walls, which allow for a vast extension of their sensing capabilities. The challenge of simultaneously enhancing the sensitivity and selectivity of nanopipettes for pH sensing remains, hindering their practical applications. Herein, we report insulin-modified nanopipettes with excellent pH response performances, which were prepared by introducing insulin onto their inner walls via a two-step reaction involving silanization and amidation. The pH response intensity based on ion current rectification was significantly enhanced by approximately 4.29 times when utilizing insulin-modified nanopipettes compared with bare ones, demonstrating a linear response within the pH range of 2.50 to 7.80. In addition, insulin-modified nanopipettes featured good reversibility and selectivity. The modification processes were monitored using the I-V curves, and the relevant mechanisms were discussed. The effects of solution pH and insulin concentration on the modification results were investigated to achieve optimal insulin introduction. This study showed that the pH response behavior of nanopipettes can be greatly improved by introducing versatile molecules onto the inner walls, thereby contributing to the development and utilization of pH-responsive nanopipettes.


Subject(s)
Insulin , Hydrogen-Ion Concentration , Insulin/chemistry , Biosensing Techniques/methods , Ions/chemistry
13.
Sensors (Basel) ; 24(13)2024 Jul 03.
Article in English | MEDLINE | ID: mdl-39001098

ABSTRACT

The quartz tuning fork (QTF) is a promising instrument for biosensor applications due to its advanced properties such as high sensitivity to physical quantities, cost-effectiveness, frequency stability, and high-quality factor. Nevertheless, the fork's small size and difficulty in modifying the prongs' surfaces limit its wide use in experimental research. Our study presents the development of a QTF immunosensor composed of three active layers: biocompatible natural melanin nanoparticles (MNPs), glutaraldehyde (GLU), and anti-IgG layers, for the detection of immunoglobulin G (IgG). Frequency shifts of QTFs after MNP functionalization, GLU activation, and anti-IgG immobilization were measured with an Asensis QTF F-master device. Using QTF immunosensors that had been modified under optimum conditions, the performance of QTF immunosensors for IgG detection was evaluated. Accordingly, a finite element method (FEM)-based model was produced using the COMSOL Multiphysics software program (COMSOL License No. 2102058) to simulate the effect of deposited layers on the QTF resonance frequency. The experimental results, which demonstrated shifts in frequency with each layer during QTF surface functionalization, corroborated the simulation model predictions. A modelling error of 0.05% was observed for the MNP-functionalized QTF biosensor compared to experimental findings. This study validated a simulation model that demonstrates the advantages of a simulation-based approach to optimize QTF biosensors, thereby reducing the need for extensive laboratory work.


Subject(s)
Biosensing Techniques , Immunoglobulin G , Melanins , Nanoparticles , Quartz , Immunoglobulin G/chemistry , Immunoglobulin G/immunology , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Nanoparticles/chemistry , Melanins/chemistry , Quartz/chemistry , Immunoassay/methods , Immunoassay/instrumentation , Computer Simulation , Antibodies, Anti-Idiotypic/immunology , Antibodies, Anti-Idiotypic/chemistry , Humans
14.
Sensors (Basel) ; 24(13)2024 Jul 03.
Article in English | MEDLINE | ID: mdl-39001101

ABSTRACT

With the development of technology, people's demand for pressure sensors with high sensitivity and a wide working range is increasing. An effective way to achieve this goal is simulating human skin. Herein, we propose a facile, low-cost, and reproducible method for preparing a skin-like multi-layer flexible pressure sensor (MFPS) device with high sensitivity (5.51 kPa-1 from 0 to 30 kPa) and wide working pressure range (0-200 kPa) by assembling carbonized fabrics and micro-wrinkle-structured Ag@rGO electrodes layer by layer. In addition, the highly imitated skin structure also provides the device with an extremely short response time (60/90 ms) and stable durability (over 3000 cycles). Importantly, we integrated multiple sensor devices into gloves to monitor finger movements and behaviors. In summary, the skin-like MFPS device has significant potential for real-time monitoring of human activities in the field of flexible wearable electronics and human-machine interaction.


Subject(s)
Cotton Fiber , Pressure , Wearable Electronic Devices , Humans , Cotton Fiber/analysis , Monitoring, Physiologic/instrumentation , Monitoring, Physiologic/methods , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Electrodes , Skin , Textiles , Human Activities
15.
Cells ; 13(13)2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38994966

ABSTRACT

Fluorescence resonance energy transfer (FRET) biosensors have proven to be an indispensable tool in cell biology and, more specifically, in the study of G-protein signalling. The best method of measuring the activation status or FRET state of a biosensor is often fluorescence lifetime imaging microscopy (FLIM), as it does away with many disadvantages inherent to fluorescence intensity-based methods and is easily quantitated. Despite the significant potential, there is a lack of reliable FLIM-FRET biosensors, and the data processing and analysis workflows reported previously face reproducibility challenges. Here, we established a system in live primary mouse pancreatic ductal adenocarcinoma cells, where we can detect the activation of an mNeonGreen-Gαi3-mCherry-Gγ2 biosensor through the lysophosphatidic acid receptor (LPAR) with 2-photon time-correlated single-photon counting (TCSPC) FLIM. This combination gave a superior signal to the commonly used mTurquoise2-mVenus G-protein biosensor. This system has potential as a platform for drug screening, or to answer basic cell biology questions in the field of G-protein signalling.


Subject(s)
Biosensing Techniques , Fluorescence Resonance Energy Transfer , Animals , Fluorescence Resonance Energy Transfer/methods , Mice , Biosensing Techniques/methods , GTP-Binding Proteins/metabolism , Humans , Pancreatic Neoplasms/metabolism , Pancreatic Neoplasms/pathology , Cell Line, Tumor , Receptors, Lysophosphatidic Acid/metabolism , Carcinoma, Pancreatic Ductal/metabolism , Carcinoma, Pancreatic Ductal/pathology
16.
Molecules ; 29(13)2024 Jun 24.
Article in English | MEDLINE | ID: mdl-38998952

ABSTRACT

The sensitivity of immunoassays is generally limited by the low signal reporter/recognition element ratio. Nanomaterials serving as the carriers can enhance the loading number of signal reporters, thus improving the detection sensitivity. However, the general immobilization strategies, including direct physical adsorption and covalent coupling, may cause the random orientation and conformational change in proteins, partially or completely suppressing the enzymatic activity and the molecular recognition ability. In this work, we proposed a strategy to load recognition elements of antibodies and enzyme labels using boronic acid-modified metal-organic frameworks (MOFs) as the nanocarriers for signal amplification. The conjugation strategy was proposed based on the boronate ester interactions between the carbohydrate moieties in antibodies and enzymes and the boronic acid moieties on MOFs. Both enzymes and MOFs could catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2, therefore achieving dual signal amplification. To indicate the feasibility and sensitivity of the strategy, colorimetric immunoassays of prostate specific antigen (PSA) were performed with boronic acid-modified Cu-MOFs as peroxidase mimics to catalyze TMB oxidation and nanocarriers to load antibody and enzyme (horseradish peroxidase, HRP). According to the change in the absorbance intensity of the oxidized TMB (oxTMB), PSA at the concentration range of 1~250 pg/mL could be readily determined. In addition, this work presented a site-specific and oriented conjugation strategy for the modification of nanolabels with recognition elements and signal reporters, which should be valuable for the design of novel biosensors with high sensitivity and selectivity.


Subject(s)
Boronic Acids , Colorimetry , Metal-Organic Frameworks , Metal-Organic Frameworks/chemistry , Colorimetry/methods , Boronic Acids/chemistry , Immunoassay/methods , Humans , Benzidines/chemistry , Oxidation-Reduction , Prostate-Specific Antigen/analysis , Hydrogen Peroxide/chemistry , Antibodies/chemistry , Biosensing Techniques/methods , Horseradish Peroxidase/chemistry , Horseradish Peroxidase/metabolism
17.
Molecules ; 29(13)2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38998965

ABSTRACT

In this study, a self-responsive fluorescence aptasensor was established for the determination of lactoferrin (Lf) in dairy products. Herein, the aptamer itself functions as both a recognition element that specifically binds to Lf and a fluorescent signal reporter in conjunction with fluorescent moiety. In the presence of Lf, the aptamer preferentially binds to Lf due to its specific and high-affinity recognition by folding into a self-assembled and three-dimensional spatial structure. Meanwhile, its reduced spatial distance in the aptamer-Lf complex induces a FRET phenomenon based on the quenching of 6-FAM by amino acids in the Lf protein, resulting in a turn-off of the fluorescence of the system. As a result, the Lf concentration can be determined straightforwardly corresponding to the change in the self-responsive fluorescence signal. Under the optimized conditions, good linearities (R2 > 0.99) were achieved in an Lf concentration range of 2~10 µg/mL for both standard solutions and the spiked matrix, as well as with the desirable detection limits of 0.68 µg/mL and 0.46 µg/mL, respectively. Moreover, the fluorescence aptasensor exhibited reliable recoveries (89.5-104.3%) in terms of detecting Lf in three commercial samples, which is comparable to the accuracy of the HPCE method. The fluorescence aptasensor offers a user-friendly, cost-efficient, and promising sensor platform for point-of-need detection.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Dairy Products , Lactoferrin , Lactoferrin/analysis , Lactoferrin/chemistry , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Dairy Products/analysis , Fluorescence , Limit of Detection , Spectrometry, Fluorescence/methods , Food Analysis/methods , Fluorescence Resonance Energy Transfer/methods
18.
Molecules ; 29(13)2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38999110

ABSTRACT

Electrochemical biosensors have emerged as powerful tools for the ultrasensitive detection of lung cancer biomarkers like carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and alpha fetoprotein (AFP). This review comprehensively discusses the progress and potential of nanocomposite-based electrochemical biosensors for early lung cancer diagnosis and prognosis. By integrating nanomaterials like graphene, metal nanoparticles, and conducting polymers, these sensors have achieved clinically relevant detection limits in the fg/mL to pg/mL range. We highlight the key role of nanomaterial functionalization in enhancing sensitivity, specificity, and antifouling properties. This review also examines challenges related to reproducibility and clinical translation, emphasizing the need for standardization of fabrication protocols and robust validation studies. With the rapid growth in understanding lung cancer biomarkers and innovations in sensor design, nanocomposite electrochemical biosensors hold immense potential for point-of-care lung cancer screening and personalized therapy guidance. Realizing this goal will require strategic collaboration among material scientists, engineers, and clinicians to address technical and practical hurdles. Overall, this work provides valuable insight for developing next-generation smart diagnostic devices to combat the high mortality of lung cancer.


Subject(s)
Biomarkers, Tumor , Biosensing Techniques , Electrochemical Techniques , Lung Neoplasms , Humans , Biomarkers, Tumor/analysis , Lung Neoplasms/diagnosis , Biosensing Techniques/methods , Electrochemical Techniques/methods , Carcinoembryonic Antigen/analysis , Carcinoembryonic Antigen/blood , Nanocomposites/chemistry , Graphite/chemistry
19.
Anal Chem ; 96(28): 11383-11389, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38946419

ABSTRACT

Apurinic/apyrimidinic endonuclease 1 (APE1), as a vital base excision repair enzyme, is essential for maintaining genomic integrity and stability, and its abnormal expression is closely associated with malignant tumors. Herein, we constructed an electrochemiluminescence (ECL) biosensor for detecting APE1 activity by combining nanoconfined ECL silver nanoclusters (Ag NCs) with X-shaped DNA recognizer-triggered cascade amplification. Specifically, the Ag NCs were prepared and confined in the glutaraldehyde-cross-linked chitosan hydrogel network using the one-pot method, resulting in a strong ECL response and exceptional stability in comparison with discrete Ag NCs. Furthermore, the self-assembled X-shaped DNA recognizers were designed for APE1 detection, which not only improved reaction kinetics due to the ordered arrangement of recognition sites but also achieved high sensitivity by utilizing the recognizer-triggered cascade amplification of strand displacement amplification (SDA) and DNAzyme catalysis. As expected, this biosensor achieved sensitive ECL detection of APE1 in the range of 1.0 × 10-3 U·µL-1 to 1.0 × 10-10 U·µL-1 with the detection limit of 2.21 × 10-11 U·µL-1, rendering it a desirable approach for biomarker detection.


Subject(s)
Biosensing Techniques , DNA-(Apurinic or Apyrimidinic Site) Lyase , Electrochemical Techniques , Luminescent Measurements , Metal Nanoparticles , Silver , DNA-(Apurinic or Apyrimidinic Site) Lyase/metabolism , DNA-(Apurinic or Apyrimidinic Site) Lyase/analysis , Silver/chemistry , Humans , Metal Nanoparticles/chemistry , Electrochemical Techniques/methods , Luminescent Measurements/methods , Biosensing Techniques/methods , Nucleic Acid Amplification Techniques/methods , DNA/chemistry , Limit of Detection , DNA, Catalytic/chemistry , DNA, Catalytic/metabolism
20.
Anal Chem ; 96(28): 11326-11333, 2024 Jul 16.
Article in English | MEDLINE | ID: mdl-38953527

ABSTRACT

Herein, the aptamer-antibody sandwich module was first introduced to accurately recognize a low molecular weight compound (mycotoxin). Impressively, compared with the large steric hindrance of a traditional dual-antibody module, the aptamer-antibody sandwich with low Gibbs free energy and a low dissociation constant has high recognition efficiency; thus, it could reduce false positives and false negatives caused by a dual-antibody module. As a proof of concept, a sensitive electrochemiluminescence (ECL) biosensor was constructed for detecting mycotoxin zearalenone (ZEN) based on an aptamer-antibody sandwich as a biological recognition element and porous ZnO nanosheets (Zn NSs) supported Cu nanoclusters (Cu NCs) as the signal transduction element, in which the antibody was modified on the vertex of a tetrahedral DNA nanostructure (TDN) with a rigid structure to increase the kinetics of target recognition for promoting the detection sensitivity. Moreover, the Cu NCs/Zn NSs exhibited an excellent ECL response that was attributed to the aggregation-induced ECL enhancement through electrostatic interactions. The sensing platform achieved trace detection of ZEN with a low detection limit of 0.31 fg/mL, far beyond that of the enzyme-linked immunosorbent assay (ELISA, the current rapid detection method) and high-performance liquid chromatography (HPLC, the national standard detection method). The strategy has great application potential in food analysis, environmental monitoring, and clinical diagnosis.


Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , Electrochemical Techniques , Zearalenone , Aptamers, Nucleotide/chemistry , Biosensing Techniques/methods , Zearalenone/analysis , Zearalenone/immunology , Electrochemical Techniques/methods , Copper/chemistry , Limit of Detection , Antibodies/chemistry , Antibodies/immunology , Luminescent Measurements/methods , Zinc Oxide/chemistry , Molecular Weight
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