Selective Biosensor Research Articles

Improved Sensitivity and Selectivity of Glutathione Detection through Target-Driven Electron Donor Generation in Photoelectrochemical Electrodes.

Glutathione (GSH) plays a vital role in many physiological processes, and its abnormal levels have been found to be associated with several diseases. In contrast to traditional methods using electron donor-containing electrolytes for photoelectrochemical (PEC) sensing, in this study, a target-driven electron donor generation in a PEC electrode was developed to detect GSH. Using well-aligned TiO2 nanotube arrays (TNTs) as the PEC substrate, mesoporous MIL-125(Ti) was grown in the TNTs through an in situ solvothermal method and subsequent two-step annealing treatment. The accommodation capacity of mesoporous MIL-125(Ti) allows a well loading of cystine and Pt nanoclusters (NCs). Taking advantage of the specific cleavage ability of disulfide bonds by GSH, cystine was converted to cysteine, which served as the electron donor for the PEC process. Benefiting from the confinement effect of mesoporous MIL-125(Ti), cysteine was effectively oxidized to cysteine sulfinic acid by the photogenerated holes. Importantly, the highly active Pt NCs decorated in the mesopores not only improved the charge transfer but also accelerated the above oxidation reaction. The synergistic effect of these factors enabled the efficient separation of the photogenerated electron-hole pairs, which induced a significant photocurrent increase and in turn led to the high-sensitivity detection of GSH. Consequently, the proposed PEC biosensor exhibited excellent performance in the detection of GSH in serum specimens. The target-driven electron donor generation designed in this study might open a new route for developing sensitive and selective PEC biosensors with application in complex biological environments.

Peptide aptamer-based polyaniline-modified amperometric biosensor for L-lysine detection in real serum samples

L-Lysine (L-Lys) quantification in serum using a novel and highly selective amperometric biosensor has been reported. In this study, an efficient, enzyme-free, and simple anti-fouling biosensor was developed based on a self-screened peptide aptamer. A glassy carbon electrode (GCE) was used to construct anti-fouling interfaces by modifying its surface with polyaniline (PANI) polymer. The peptide aptamer, Cys-Pro-Pro-Pro-Pro-Arg-Glu-Asn-Ile-Gln-Arg-Leu-Thr, was then immobilized onto this electrode via an electroactive cysteine linker and its potential in the determination of L-Lys was examined. Under optimised experimental conditions, the peptide-modified electrodes exhibited excellent anti-fouling and electrochemical sensing. The biosensor was effective in resisting biofouling in a wide range of serum samples and amino acid solutions, and its linear range for L-Lys detection ranged from 1 nM to 10 mM, with a comparatively lower detection limit (0.3 nM; S/N = 3). The anti-fouling biosensor could detect L-Lys in real serum samples, and this approach of designing peptide aptamers basedlow-fouling biosensorscan easily be extended to the development of a bio-sensing platform system for a variety of other metabolites.

Au/NG/SWCNTs/FTO-glass modified electrode based electrochemical biosensor for DNA detection

An easy, quick, and efficient detection of Multidrug Resistance (MDR) of cancer cells at the clinical level is the need of the hour for the effective treatment of leukemia patients. In this study, we reported carbon nanomaterials-based biosensors based on Au nanoparticles (Au-NPs) decorated on Nitrogen-doped Graphene (NG) and Single-Walled Carbon Nanotubes (SWCNTs) for effective, efficient, and sensitive detection of affected DNA. Three Au/NG/SWCNT-based Modified Electrode (ME) were made containing 2, 4, and 6 mg SWCNTs. The thiol group attached at the 5′end was immobilized at ME due to a strong bond between the Au-NPs and thiol group. NG/SWCNTs enhanced the performance of the composite due to its better sensitivity and fast electron transport. Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV), and Differential Potential Voltammetry (DPV) analysis were performed to monitor the performance of the sensor after the hybridization of target DNA onto the capture probe on the modified electrode surface. Different target DNA sequences were used to check the selectivity and sensitivity of the fabricated biosensor. The selectivity performance of prepared DNA sensors was also proved to be good shown by DPV results. The findings of this study provide insights for developing new highly sensitive, selective, and cost-effective portable biosensors for MDR gene detection, which will enable the early diagnosis of cancer more effective at the clinical level. Compared with previous DNA sensors with oligonucleotides directly incorporated on carbon electrodes, this carbon nanotube-based assay with its large surface area and good charge-transport characteristics dramatically increased DNA attachment quantity and complementary DNA detection sensitivity.

Highly Sensitive Naked Eye Detectable Colorimetric Biosensors Made from Macroporous Framework Melamine Foams for Onsite and Simultaneous Detection of Multiple Environmental Hazards in Flowing Through Sensing Systems

AbstractPersonal‐use, naked eye‐readable, low‐cost, highly sensitive, and selective biosensors for rapid detection of environmental toxicants are relevant for many application scenarios. Here, the recent developments of highly sensitive and naked eye distinguishable colorimetric sensors by using commercially available melamine foam (MF) as basic sensing materials for instant and volume‐responsive simultaneous detection of multiple targets in fluid systems are reported. The MF possesses a unique reticulated three‐dimensional (3D) macroporous framework structure enabling rapid mass transfer of large biomolecules through the structures in all directions, ensuring easy access of numerous active binding sites of the chemically modified framework to the proteins and target molecules, and subsequently providing significantly increased sensitive and volume‐responsive detection of target molecules in flowing through sensor systems. Promising results in direct, sandwich, and competitive ELISA tests demonstrated the great application potential of the materials. Besides, an additive and simultaneous detection of two targets in one system is achieved by using different layers of the sensor materials in a flowing‐through filtering device. The novel biosensors are expected to significantly improve the sensitivity and broaden the applications of ELISA in the rapid detections of trace amounts of toxicants in liquid and aerosol systems.

A Y-shape-structured electrochemiluminescence biosensor based on carbon quantum dots and locked nucleic acid probe for microRNA determination with single-base resolution

Since microRNAs (miRNAs) are predictors of tumorigenesis, accurate identification and quantification of miRNAs with highly similar sequences are expected to reflect tumor diagnosis and treatment. In this study, a highly selective and sensitive electrochemiluminescence (ECL) biosensor was constructed for miRNAs determination based on Y-shaped junction structure equipped with locked nucleic acids (LNA), graphene oxide-based nanocomposite to enrich luminophores, and conductive matrix. Specifically, two LNA-modified probes were designed for specific miRNA recognition, that is, a dual-amine functionalized hairpin capture probe and a signal probe. A Y-shaped DNA junction structure was generated on the electrode surface upon miRNA hybridizing across the two branches, so as to enhance the selectivity. Carbon quantum dots-polyethylene imine-graphene oxide (CQDs-PEI-GO) nanocomposites were developed to enrich luminophores CQDs, and thus enhancing the ECL intensity. For indirect signal amplification, an electrochemically activated poly(2-aminoterephthalic acid) (ATA) film decorated with gold nanoparticles was prepared on electrode as an effective matrix to accelerate the electron transfer. The fabricated ECL biosensor achieved sensitive determination of miRNA-222 with a limit-of-detection (LOD) as low as 1.95 fM (S/N = 3). Notably, Y-shaped junction structures equipped with LNA probes endowed ECL biosensor with salient single-base discrimination ability and anti-interference capacity. Overall, the proposed Y-shaped ECL biosensor has considerable promise for clinical biomarker determination.

Pushing the Limits of Biosensing: Selective Calcium Ion Detection with High Sensitivity via High-k Gate Dielectric Engineered Si Nanowire Random Network Channel Dual-Gate Field-Effect Transistors.

Calcium ions (Ca2+) are abundantly present in the human body; they perform essential roles in various biological functions. In this study, we propose a highly sensitive and selective biosensor platform for Ca2+ detection, which comprises a dual-gate (DG) field-effect transistor (FET) with a high-k engineered gate dielectric, silicon nanowire (SiNW) random network channel, and Ca2+-selective extended gate. The SiNW channel device, which was fabricated via the template transfer method, exhibits superior Ca2+ sensing characteristics compared to conventional film channel devices. An exceptionally high Ca2+ sensitivity of 208.25 mV/dec was achieved through the self-amplification of capacitively coupled DG operation and an enhanced amplification ratio resulting from the high surface-to-volume ratio of the SiNW channel. The SiNW channel device demonstrated stable and reliable sensing characteristics, as evidenced by minimal hysteresis and drift effects, with the hysteresis voltage and drift rate measuring less than 6.53% of the Ca2+ sensitivity. Furthermore, the Ca2+-selective characteristics of the biosensor platform were elucidated through experiments with pH buffer, NaCl, and KCl solutions, wherein the sensitivities of the interfering ions were below 7.82% compared to the Ca2+ sensitivity. The proposed Ca2+-selective biosensor platform exhibits exceptional performance and holds great potential in various biosensing fields.

Aptameric Fluorescent Biosensors for Liver Cancer Diagnosis.

Liver cancer is a prevalent global health concern with a poor 5-year survival rate upon diagnosis. Current diagnostic techniques using the combination of ultrasound, CT scans, MRI, and biopsy have the limitation of detecting detectable liver cancer when the tumor has already progressed to a certain size, often leading to late-stage diagnoses and grim clinical treatment outcomes. To this end, there has been tremendous interest in developing highly sensitive and selective biosensors to analyze related cancer biomarkers in the early stage diagnosis and prescribe appropriate treatment options. Among the various approaches, aptamers are an ideal recognition element as they can specifically bind to target molecules with high affinity. Furthermore, using aptamers, in conjunction with fluorescent moieties, enables the development of highly sensitive biosensors by taking full advantage of structural and functional flexibility. This review will provide a summary and detailed discussion on recent aptamer-based fluorescence biosensors for liver cancer diagnosis. Specifically, the review focuses on two promising detection strategies: (i) Förster resonance energy transfer (FRET) and (ii) metal-enhanced fluorescence for detecting and characterizing protein and miRNA cancer biomarkers.

Albumin nanoparticles with tunable ultraviolet-to-red autofluorescence for label-free cell imaging and selective biosensing of copper ion

Early and simple detection of aberrant cooper metabolism in diseases with neurological-manifestations and several other conditions, including cancer, becomes an urgent necessity. Instrumental methods used today are limited to high-cost equipment and reagents and demand highly qualified personnel. In this work, we report easy-to-use and cost-effective nano-sized sensors for the selective and quantitative detection of copper ion based on fluorescence quenching. Glutaraldehyde cross-linked albumin nanoparticles with tunable ultraviolet-to-red autofluorescence emissions are developed as dual-agents for sensing and imaging. These albumin nanoparticles show great selectivity towards copper ion when tested against a selection of biochemical components and other metal ions, and a limit of detection as low as 1.9 μM, relevant for sensing in clinical diagnosis, was determined. In addition, a lack of toxicity and good cellular uptake were observed and the ultraviolet-to-red intrinsic fluorescence of the albumin nanoparticles was preserved when tested in vitro on NIH:OVCAR3 cell line. Preliminary studies confirm the albumin nanoparticles' ability to detect Cu2+in vitro and establishes their potential for future practical use.

Molybdenum-cobalt micro-nano interface assisted ultrasensitive and selective non-enzymatic glucose biosensor

In the present work, we report highly sensitive and selective non-enzymatic glucose biosensor using novel hybrid CoOOH nanospheres decorated MoO3 nanobelts (MoCo). MoCo nanocomposite exhibits superior sensing properties toward glucose detection due to its improved electron transfer capability along with the large surface area. The biosensor achieved an excellent linear range within the concentration of 0.001–1.0 mM correspond to the amperometric current response was obtained from GCE/MoCo/Nafion electrode. The biosensing electrode is resulted a linear regression coefficient (R2 = 0.9959) and limit of detection (LOD) is 56 µM at (S/N = 3). The performance optimization of the biosensor was performed at a different operating temperature subjected to successive glucose additions. A remarkable selectivity is obtained against to the glucose at presence of different interfering substance and long-term stability of 30 days reached without a noticeable decay in the amperometric current response.

A highly selective and sensitive sensor for promethazine based on molecularly imprinted interface coated Au/Sn bimetal nanoclusters functionalized acupuncture needle microelectrode

Promethazine (PMZ) is an effective antihistamine that is used as a nerve tranquilizer to treat mental disorders. However, drug abuse causes harm to the human body and also pollutes the environment to a certain extent. Therefore, it is crucial to develop a highly selective and sensitive biosensor for PMZ determination. An acupuncture needle (AN) was used as an electrode in 2015, and further research on the electrode's essence in electrochemistry is needed. In this work, a sensor based on a surface imprinted film coordinated Au/Sn biometal was first fabricated on AN via electrochemistry. The obtained cavities showed complementary and suitable sites for “N atom” electron transfer through the phenyl ring structure in promethazine, which is rigorous for the configuration near the interface. Under the optimal conditions, MIP/Au/Sn/ANE exhibits a good linear relationship in the range of 0.5 μM–500 μM, and the detection limit (LOD) is 0.14 μM (S/N = 3). The sensor exhibits good repeatability, stability, and selectivity and can be successfully used to analyze and detect PMZ in human serum and environmental water. The findings are scientifically significant for AN electrochemistry and the sensors have potential for in vivo medicamentosus monitoring in the future.

Development of Molecularly Imprinted Polymer Nanoparticles with High Affinity and Its Application to Electrochemical Biosensors

In this study, redox-labeled molecularly imprinted polymer nanoparticles (nano-MIPs) were synthesized using a solid-phase approach, templated with biomarkers for diabetes such as human serum albumin (HSA). The purpose of this research was to develop enzyme-/antibody-free electrochemical biosensors with the nano-MIP-coated Au electrodes. The synthesized HSA–nano-MIP (HNM) was analyzed for its chemical composition, size, affinity, and electrochemical property, and was tethered on gold via a coupling chemistry. The results of cyclic voltammetry analysis revealed that electron transfer occurred on the HNM-immobilized Au electrode through physical displacement of the redox centers within HNM, which hopped from one redox center to an adjacent redox center, a process known as bounded diffusion. In this paper, we present a promising approach to developing sensitive and selective electrochemical biosensors for diabetes detection.

Aptamer-Based Electrochemical Microfluidic Biosensor for the Detection of Cryptosporidium parvum.

Cryptosporidium parvum is a high-risk and opportunistic waterborne parasitic pathogen with highly infectious oocysts that can survive harsh environmental conditions for long periods. Current state-of-the-art methods are limited to lengthy imaging and antibody-based detection techniques that are slow, labor-intensive, and demand trained personnel. Therefore, the development of new sensing platforms for rapid and accurate identification at the point-of-care (POC) is essential to improve public health. Herein, we propose a novel electrochemical microfluidic aptasensor based on hierarchical 3D gold nano-/microislands (NMIs), functionalized with aptamers specific to C. parvum. We used aptamers as robust synthetic biorecognition elements with a remarkable ability to bind and discriminate among molecules to develop a highly selective biosensor. Also, the 3D gold NMIs feature a large active surface area that provides high sensitivity and a low limit of detection (LOD), especially when they are combined with aptamers,. The performance of the NMI aptasensor was assessed by testing the biosensor's ability to detect different concentrations of C. parvum oocysts spiked in different sample matrices, i.e., buffer, tap water, and stool, within 40 min detection time. The electrochemical measurements showed an acceptable LOD of 5 oocysts mL-1 in buffer medium, as well as 10 oocysts mL-1 in stool and tap water media, over a wide linear range of 10-100,000 oocysts mL-1. Moreover, the NMI aptasensor recognized C. parvum oocysts with high selectivity while exhibiting no significant cross-reactivity to other related coccidian parasites. The specific feasibility of the aptasensor was further demonstrated by the detection of the target C. parvum in patient stool samples. Our assay showed coherent results with microscopy and real-time quantitative polymerase chain reaction, achieving high sensitivity and specificity with a significant signal difference (p < 0.001). Therefore, the proposed microfluidic electrochemical biosensor platform could be a stepping stone for the development of rapid and accurate detection of parasites at the POC.

Review: Electrochemical biosensors based on ZnO nanostructures

In the last few decades’ electrochemical biosensors have witnessed vast developments due to the broad range of different applications, including health care and medical diagnosis, environmental monitoring and assessment, food industry, and drug delivery. Integration of nanostructured material with different disciplines and expertise of electrochemistry, solid-state physics, material science, and biology has offered the opportunity of a future generation of highly rapid, sensitive, stable, selective, and novel electrochemical biosensor devices. Among metal oxide nanomaterials, ZnO nanostructures are one of the most important nanomaterials in today’s nanotechnology research. Such nanostructures have been studied intensely not only for their extraordinary structural, optical, and electronic properties but also for their prominent performance in diverse novel applications such as photonics, optics, electronics, drug delivery, cancer treatment, bio-imaging, etc. However, functionality of these nanomaterials is eventually dictated by the capability to govern their properties including shape, size, position, and crystalline structure on the nanosized scale. This review aims to update the outstanding advancement in the developments of the enzymatic and non-enzymatic biosensors using a different structure of ZnO nanomaterials. After a coverage of the basic principles of electrochemical biosensors, we highlight the basic features of ZnO as a potential anticancer agent. focused attention gives to functionalized biosensors based on ZnO nanostructures for detecting biological analytes, such as glucose, cholesterol, L-lactic acid, uric acid, metal ions, and pH.

Vanadium‐Incorporated Mesoporous Silica as Oxidase Mimic for Colorimetric Dopamine Detection and Anticancer Activity

AbstractThe intriguing features of artificial enzymes made nanozymes attractive in the field of biosensing and biomedical. Here, vanadium‐incorporated dendritic mesoporous silica (VMSN) as an oxidase mimicking nanozyme was utilized as a sensitive and selective colorimetric biosensor to detect dopamine (DA) and treat cancer cells. The nanozyme was successfully fabricated through the in‐situ incorporation of vanadium ions in the silica framework via a simple sol‐gel method using CTAB and mesitylene. The excellent oxidase‐like activity of VMSN was monitored by the oxidation of TMB. The kinetics, mechanism of the catalytic reaction and the effect of temperature, pH, and concentration on oxidase‐like activity were investigated thoroughly and further, based on the oxidase‐like activity, a fast and sensitive colorimetric sensing of dopamine developed with a LOD of 0.0021 μM and a linear range of 0–50 μM. The proposed colorimetric method was successfully used to determine DA concentration in commercially available dopamine hydrochloride injection.VMSN was further modified with folic acid and utilized against cancer cells in vitro. Neuroblastoma cells (SHSY‐5Y) show ROS generated by VMSN in the presence of oxygen, leading to enhanced cytotoxicity detrimental for SHSY‐5Y cells.

Development, Characterization, and Structural Analysis of a Genetically Encoded Red Fluorescent Peroxynitrite Biosensor.

Boronic acid-containing fluorescent molecules have been widely used to sense hydrogen peroxide and peroxynitrite, which are important reactive oxygen and nitrogen species in biological systems. However, it has been challenging to gain specificity. Our previous studies developed genetically encoded, green fluorescent peroxynitrite biosensors by genetically incorporating a boronic acid-containing noncanonical amino acid (ncAA), p-boronophenylalanine (pBoF), into the chromophore of circularly permuted green fluorescent proteins (cpGFPs). In this work, we introduced pBoF to amino acid residues spatially close to the chromophore of an enhanced circularly permuted red fluorescent protein (ecpApple). Our effort has resulted in two responsive ecpApple mutants: one bestows reactivity toward both peroxynitrite and hydrogen peroxide, while the other, namely, pnRFP, is a selective red fluorescent peroxynitrite biosensor. We characterized pnRFP in vitro and in live mammalian cells. We further studied the structure and sensing mechanism of pnRFP using X-ray crystallography, 11B-NMR, and computational methods. The boron atom in pnRFP adopts an sp2-hybridization geometry in a hydrophobic pocket, and the reaction of pnRFP with peroxynitrite generates a product with a twisted chromophore, corroborating the observed "turn-off" fluorescence response. Thus, this study extends the color palette of genetically encoded peroxynitrite biosensors, provides insight into the response mechanism of the new biosensor, and demonstrates the versatility of using protein scaffolds to modulate chemoreactivity.

Glucose determination in human serum by applying inner filter effect quenching mechanism of upconversion nanoparticles.

Accurate blood glucose determination is essential to the clinical diagnosis and management of diabetes. This work establishes an inner filter effect (IFE) strategy between upconversion nanoparticles (UCNPs) and quinone-imine complex for glucose monitoring in human serum simply and efficiently. In this system, the enzyme glucose oxidase (GOx) catalyzes the reaction of glucose into hydrogen peroxide (H2O2) and gluconic acid when compulsion by oxygen. In the presence of horseradish peroxidase (HRP), the produced H2O2 can catalytically oxidize phenol and 4-amino antipyrine (4-AAP) to generate quinone-imine products. The purple-colored quinone-imine complex effectively absorbed the fluorescence of NaYF4:Yb3+, Er3+ UCNPs, leading to the strong fluorescence quenching of UCNPs through IFE. Thus, a new approach was established for glucose monitoring by determining the fluorescence intensity. Under the optimal condition, this approach shows better linearity to glucose from 2-240μmol/L with a low detection limit at 1.0μmol/L. Owing to the excellent fluorescence property and background-free interference of the UCNPs, the biosensor was applied for glucose measurements in human serum and got a satisfactory result. Furthermore, this sensitive and selective biosensor revealed great potential for the quantitative analysis of blood glucose or different kinds of H2O2-involved biomolecules for the application of clinical diagnosis.

Colorimetric detection of mercury (Hg2+) using UV-vis spectroscopy and digital image analysis based on gold nanoparticles functionalized with bromelain enzyme.

A very sensitive and selective colorimetric biosensor for the measurement of mercury ion (Hg2+) in environmental samples has been developed using functionalized gold nanoparticles with bromelain enzyme (brn-AuNPs). This work has shown that Hg2+ measurement based on spectrophotometer and digital image analysis is a very innovative and successful method for providing an effective preliminary system and has promise for the future of water quality biomonitoring. Response Surface Methodology (RSM), a Box-Behnken design-based technique, was used to identify the optimum levels of functionalization of bromelain to AuNPs. The created model's validity was confirmed, and statistical analysis revealed that the ideal functionalize conditions were 1mM of AuNPs, functionalize with 0.59mM bromelain concentration on 14℃ temperature and 72h incubation time. The lowest colorimetric detection concentration (LOD) of brn-AuNPs of Hg2+ was 0.0092ppm and 0.011ppm for spectrophotometer and digital image analysis. As shown, digital image analysis had advantages based on the LOD result comparable to UV-VIS spectrophotometer. The practical application of the brn-AuNPs sensing was proven with mercury determination in water samples. The present study developed a robust sensor, which successfully implemented in a compact portable sensor kit, turning this sensor into a very potent tool for the development water quality biomonitoring system of Hg2+ application.

Tetraphenylethylene-based giant emissive hexagonal metallaprisms for biomolecule sensing

The development of giant emissive metallacages is not only a synthetic challenge but also important for their applications. Herein, we report a type of tetraphenylethylene (TPE)-based emissive hexagonal metallaprism with diameters as large as 3.7 nm, which represents one of the largest TPE-based metallacages. They can interact with polymers and small molecules via electrostatic interactions in different modes. They form dense aggregations with DNA, which would inhibit the molecular motions and offer enhanced emission. However, photoinduced electron transfer from nucleotides to metallaprisms occurs after complexation, so they show decreased emission for ATP and ADP. This study provides a type of giant emissive metallaprism for selective biosensing, which will guide the future design of metallacages for bio-applications.

The Integration of Field Effect Transistors to Microfluidic Devices

Devices that integrate field effect transistors into microfluidic channels are becoming increasingly promising in the medical, environmental, and food realms, among other applications. The uniqueness of this type of sensor lies in its ability to reduce the background signals existing in the measurements, which interfere in obtaining good limits of detection for the target analyte. This and other advantages intensify the development of selective new sensors and biosensors with coupling configuration. This review work focused on the main advances in the fabrication and application of field effect transistors integrated into microfluidic devices as a way of identifying the potentialities that exist in these systems when used in chemical and biochemical analyses. The emergence of research on integrated sensors is not a recent study, although more recently the progress of these devices is more accentuated. Among the studies that used integrated sensors with electrical and microfluidic parts, those that investigated protein binding interactions seem to be the ones that expanded the most due, among other things, to the possibility of obtaining several physicochemical parameters involved in protein–protein interactions. Studies in this area have a great possibility of advancing innovations in sensors with electrical and microfluidic interfaces in new designs and applications.

Recent Advances in Aptamer-Based Sensors for Sensitive Detection of Neurotransmitters.

In recent years, there has been an increased demand for highly sensitive and selective biosensors for neurotransmitters, owing to advancements in science and technology. Real-time sensing is crucial for effective prevention of neurological and cardiovascular diseases. In this review, we summarise the latest progress in aptamer-based biosensor technology, which offers the aforementioned advantages. Our focus is on various biomaterials utilised to ensure the optimal performance and high selectivity of aptamer-based biosensors. Overall, this review aims to further aptamer-based biosensor technology.