Food safety as a huge world public health threat has attracted increasing attention. Effective detection methods are of great importance to ensure food safety. However, the development of reliable ...and efficient detection methods has been a challenging task because of the complexity of food matrices and trace levels of food contaminants. Recently, emerging nanomaterials with mimetic enzyme activity, namely, nanozymes, have been employed for novel biosensor development, which has greatly accelerated the advancement of food safety assay. In this review, we summarize the mechanism and advances in nanozyme-based biosensors such as colorimetric biosensors, fluorescence biosensors, chemiluminescent biosensors, electrochemical biosensors, SERS-based biosensors, and other biosensors. Impressively, the applications of the nanozyme-based biosensors in food safety screening have also been comprehensively summarized (including mycotoxins, antibiotics, pesticides, pathogens, intentional adulteration, metal ions, and others). In the end, future opportunities and challenges in this promising field are tentatively proposed.
Construction of nanozyme-based biosensors and their applications in the food safety assay. Display omitted
•Emerging nanozyme-based biosensors are promising for food safety assay.•Progress in the construction of nanozyme-based biosensors was reviewed.•Applications of these biosensors to food safety assay were summarized.•Challenges and opportunities of the use of these biosensors were discussed and prospected.
Magnetic nanobeads have been widely used for magnetic separation, target labeling and signal amplification in the development of various biosensors. This review summarized (1) the basic knowledge of ...magnetic nanobeads, including physical structure, chemical characteristics and surface modification; (2) the development and applications of magnetic separation, from the earliest conventional magnetic separation, to high gradient magnetic separation, then to magnetophoretic separation and magnetic continuous-flow separation, finally to the latest magnetic grid separation; and (3) recent advances and applications of magnetic nanobead based biosensors, where the magnetic nanobeads work as either detection signal for electromagnetic biosensors, magnetic lateral flow biosensors and magnetic relaxation switching biosensors, or signal amplifying tag for electrochemical biosensors, QCM biosensors and SPR biosensors, or both. Besides, the important issues and future trends for magnetic nanobead based separation and biosensor were also discussed and summarized.
•Basic knowledge of magnetic nanobeads were summarized.•Recent advances on MNBs for magnetic separation were reviewed.•Recent advances on MNBs for target label were reviewed.•Recent advances on MNBs for signal amplification were reviewed.
Common viral infections start from binding of the viral pathogens to the viral receptors on the host body, for example, SARS-CoV-2 infects cells by binding to human angiotensin converting enzyme 2 ...(ACE2). This review discusses optical biosensors that exploit ACE2 or ACE2 derived peptides (ACE2 mimics) as affinity ligands for detecting SARS-CoV-2. In these biosensors, the target analytes can include surrogate pseudoviruses, inactivated SARS-CoV-2 virus, spike proteins, or receptor binding domain (RBD) of the spike protein. The advantages of using ACE2 and/or ACE2 mimics over common affinity ligands (e.g. antibodies) against future virus mutations are highlighted. The advantages of the smaller sized ACE2 mimics relative to ACE2 protein for achieving more versatile sensor designs and higher selectivity are also discussed. In addition to SARS-CoV-2 detection, this review also discusses the expanded application of ACE2-based optical biosensors for the detection of non-viral targets, e.g., SARS-CoV-2 neutralising antibodies and anti-SARS-CoV-2 drugs.
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•Designs of optical biosensors utilising viral receptor ACE2 are presented.•Use of ACE2 and ACE2 mimics opens new designs of optical viral biosensors.•Applications in detection of virus, viral antigens, neutralising antibodies, and drugs are discussed.•Sensing performance of different designs of optical biosensors are compared.•Advantages of optical biosensors utilising viral receptors are highlighted.
Nanomaterials have been widely applied in the preparation of electroanalytical biosensors. Due to their small size effect, quantum size effect and surface and interface effect, nanomaterials can ...remarkably improve the important performance indexes of biosensors, such as stability, repeatability and sensitivity. Furthermore, as a result of different composition, morphology and size of all kinds of nanomaterials, they play the different roles in the process of the construction of the biosensors. In this review, the role of nanomaterials in electroanalytical biosensors used as the main line, a summary of 105 articles generalizes the main research achievement of electroanalytical biosensors.
Since the 1970s, a great deal of attention has been paid to the development of semiconductor-based biosensors because of the numerous advantages they offer, including high sensitivity, faster ...response time, miniaturization, and low-cost manufacturing for quick biospecific analysis with reusable features. Commercial biosensors have become highly desirable in the fields of medicine, food, and environmental monitoring as well as military applications, whereas increasing concerns about food safety and health issues have resulted in the introduction of novel legislative standards for these sensors. Numerous devices have been developed for monitoring biological processes such as nucleic acid hybridization, protein⁻protein interaction, antigen⁻antibody bonds, and substrate⁻enzyme reactions, just to name a few. Since the 1980s, scientific interest moved to the development of semiconductor-based devices, which also include integrated front-end electronics, such as the extended-gate field-effect transistor (EGFET) biosensor, one of the first miniaturized chemical sensors. This work is intended to be a review of the state of the art focused on the development of biosensors and chemosensors based on extended-gate field-effect transistor within the field of bioanalytical applications, which will highlight the most recent research reported in the literature. Moreover, a comparison among the diverse EGFET devices will be presented, giving particular attention to the materials and technologies.
Biosensors are a very active research field. They have the potential to lead to low-cost, rapid, sensitive, reproducible, and miniaturized bioanalytical devices, which exploit the high binding ...avidity and selectivity of biospecific binding molecules together with highly sensitive detection principles. Of the optical biosensors, those based on chemical luminescence detection (including chemiluminescence, bioluminescence, electrogenerated chemiluminescence, and thermochemiluminescence) are particularly attractive, due to their high-to-signal ratio and the simplicity of the required measurement equipment.
Several biosensors based on chemical luminescence have been described for quantitative, and in some cases multiplex, analysis of organic molecules (such as hormones, drugs, pollutants), proteins, and nucleic acids. These exploit a variety of miniaturized analytical formats, such as microfluidics, microarrays, paper-based analytical devices, and whole-cell biosensors. Nevertheless, despite the high analytical performances described in the literature, the field of chemical luminescence biosensors has yet to demonstrate commercial success.
This review presents the main recent advances in the field and discusses the approaches, challenges, and open issues, with the aim of stimulating a broader interest in developing chemical luminescence biosensors and improving their commercial exploitation.
•Biosensors are a very active research field.•Several biosensors based on chemical luminescence have been described.•We present advances in the field and discuss approaches, challenges, and open issues.
Two‐dimensional materials have allowed for great advances in the biosensors field and to obtain sophisticated, smart, and miniaturized devices. In this work, we optimized a highly sensitive and ...selective phenol biosensor using 2D pnictogens (phosphorene, arsenene, antimonene, and bismuthene) as sensing platforms. Exfoliated pnictogen were obtained by the shear‐force method, undergoing delamination and downsizing to thin nanosheets. Interestingly, compared with the other tested elements, antimonene exhibited the highest degree of exfoliation and the lowest oxidation‐to‐bulk ratio, to which we attribute its enhanced performance in the phenol biosensor system reported here. The proposed design represents the first biosensor approach developed using exfoliated pnictogens beyond phosphorene.
Biosensors based on thin nanosheets of 2D antimonene were used for phenol detection. This phenol biosensor shows enhanced analytical performance when compared to the other pnictogens in terms of linearity, sensitivity, selectivity, and reproducibility.
•We developed a noninvasive smartphone based biosensor for urea using saliva as sample, which is first such report.•The sensor was fabricated by co-immobilization of urease & pH indicator on filter ...paper strip which changed color with reaction to salivary urea.•This color change can be used to deduce urea concentration using smartphone based application by reading RGB levels.•Clinical validation carried out on spiked or clinical saliva samples show great possibility of using the biosensor for diagnosis of uremia and CKD.
In the present study, we have developed a smartphone based handheld optical biosensor for determination of urea in saliva. A simple strategy was adopted by immobilization of urease enzyme along with a pH indicator on a filter paper based strip. The strip changed color upon the reaction with urea present in saliva and the color change can be estimated using our smartphone based application based on RGB profiling. Calibration of the biosensor was carried out using spiked saliva samples and an exponentially decreasing calibration curve has been obtained for green pixel intensity in the broad range (10–1000 mgdL−1) with a linear detection range of 10–260 mgdL−1 and a response time of 20 s. The sensitivity reported for the biosensor in the clinically significant range was −0.005 average pixels sec−1/mgdL−1 with a LOD of 10.4 mgdL−1. Studies carried out on spiked saliva samples showed a good correlation between salivary urea estimated using our biosensor against phenol-hypochlorite based spectroscopic procedure. Development of a smartphone based biosensor for urea estimation eliminates the need for procuring a dedicated instrument as well as trained technician for daily monitoring and saves time as compared to traditional laboratory methods of analysis.
Recently, highly sensitive and selective biosensors have become necessary for improving public health and well‐being. To fulfill this need, high‐performance biosensing systems based on various ...nanomaterials, such as nanoparticles, carbon nanomaterials, and hybrid nanomaterials, are developed. Numerous nanomaterials show excellent physical properties, including plasmonic, magnetic, catalytic, mechanical and fluorescence properties and high electrical conductivities, and these unique and beneficial properties have contributed to the fabrication of high‐performance biosensors with various applications, including in optical, electrical, and electrochemical detection platforms. In addition, these properties can be transformed to signals for the detection of biomolecules. In this review, various types of nanomaterial‐based biosensors are introduced, and they show high sensitivity and selectivity. In addition, the potential applications of these sensors on the biosensing of several types of biomolecules are also discussed. These nanomaterials‐based biosensing systems provide a significant improvement on healthcare including rapid monitoring and early detection of infectious disease for public health.
Numerous nanomaterials are investigated, and they are applied for various sensing fields based on their amazing properties. Especially, in order to develop the highly sensitive and selective biosensing systems, multi‐functional nanomaterials are utilized as signal transducers for the various detection systems including optical, electrical, electrochemical sensing platforms. And they show excellent potential in biosensing fields.
Detection of pathogens, e.g., bacteria and viruses, is still a big challenge in analytical medicine due to their vast number and variety. Developing strategies for rapid, inexpensive, specific, and ...sensitive detection of the pathogens using nanomaterials, integrating with microfluidics devices, amplification methods, or even combining these strategies have received significant attention. Especially, after the health-threatening COVID-19 outbreak, rapid and sensitive detection of pathogens became very critical. Detection of pathogens could be realized with electrochemical, optical, mass sensitive, or thermal methods. Among them, electrochemical methods are very promising by bringing different advantages, i.e., they exhibit more versatile detection schemes and real-time quantification as well as label-free measurements, which provides a broader application perspective. In this review, we discuss the recent advances for the detection of bacteria and viruses using electrochemical biosensors. Moreover, electrochemical biosensors for pathogen detection were broadly reviewed in terms of analyte, bio-recognition and transduction elements. Different fabrication techniques, detection principles, and applications of various pathogens with the electrochemical biosensors were also discussed.
•Detection of pathogens is still a big challenge in analytical medicine due to their vast number and variety.•We discuss the recent advances for the detection of bacteria and viruses using electrochemical biosensors.•Applications of different types of nanomaterials and polymers with different surface modifications have been reviewed.
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