Advanced electrocatalytic materials based biosensors for cancer cell detection – A review

Herein, we have highlighted the latest developments on biosensors for cancer cell detection. Electrochemical (EC) biosensors offer several advantages such as high sensitivity, selectivity, rapid analysis, portability, low-cost, etc. Generally, biosensors could be classified into other basic categories such as immunosensors, aptasensors, cytosensors, electrochemiluminescence (ECL), and photo-electrochemical (PEC) sensors. The significance of the EC biosensors is that they could detect several biomolecules in human body including cholesterol, glucose, lactate, uric acid, DNA, blood ketones, hemoglobin, and others. Recently, various EC biosensors have been developed by using electrocatalytic materials such as silver sulfide (Ag₂S), black phosphene (BPene), hexagonal carbon nitrogen tube (HCNT), carbon dots (CDs)/cobalt oxy-hydroxide (CoOOH), cuprous oxide (Cu₂O), polymer dots (PDs), manganese oxide (MnO₂), graphene derivatives, and gold nanoparticles (Au-NPs). In some cases, these newly developed biosensors could be able to detect cancer cells with a limit of detection (LOD) of 1 cell/mL. In addition, many remaining challenges have to be addressed and validated by testing more real samples and confirm that these EC biosensors are more accurate and reliable to measure cancer cells in the blood and salivary samples.     

Applications and Recent Developments in the use of Antibodies for Analysis

ABSTRACT

There are many compounds that require analysis ranging from pesticide levels in corn to disease markers in human patients. There are copious challenges to be met when measuring analytes such as the matrix in which they are to be determined, the amounts present, the cost and the rapidity of the result required. Enzyme immunoassays, immunoaffinity chromatography, immunomagnetic polymerase chain reaction, flow cytometry and immunobiological biosensors have all characteristics that can enhance analytical techniques. Antibody-based methods have found applications in a large number of diverse areas such as food and water analysis, clinical diagnosis and therapeutics The structure and modes of production of antibodies and antibody-based derivatives is described and their applications in analysis critically examined.     

Laccase Containing Sol-Gel Based Optical Biosensors

Abstract

Laccase-containing sol-gels were synthesized by hydrolysis and condensation-polymerization of tetramethylorthosilicates. Two types of laccase containing sol-gel based optical biosensors were designed and tested. The first type is based on 2–8 mm thick monolith sol-gel blocks. It was observed that laccase-containing sol-gel blocks accumulate high molecular weight products of oxidation of the laccase substrate - 2,6-dimethoxyphenol. This leads to at least ten fold increase of optical bioassay sensitivity in comparison with the homogeneous phase. The response time of such biosensors is 3–24 hours. The second type of biosensor is based on laccase-containing 0.3 mm diameter solgel particles in a flow cell and includes an optical fiber measuring system. This sensor is characterized by a fast response time in comparison with the first type. The latter biosensor also possesses a homogeneous phase assay sensitivity and yields a linear calibration curve.

     

Advanced carbon nanomaterials for electrochemiluminescent biosensor applications

Electrochemiluminescent biosensors are nowadays an established technology in the field of immunosensors and diagnostics. Along with the advent of nanotechnology, the marriage between electrochemiluminescence and nanomaterials results in promising enhancing strategies in many biosensor applications. Among nanomaterials, carbon-based ones are the most used, as (i) scaffolds, (ii) luminophores and (iii) electrode materials of the sensor. In this review, we describe the importance of a rational modification and functionalization of carbon nanomaterials to optimize electrochemiluminescence signal, and we also resume the latest and most relevant applications of electrochemiluminescent biosensors based on carbon nanomaterials.     

Screen-printed electrodes for biosensing: a review (2008–2013)

Screen-printing is one of the most promising approaches towards simple, rapid and inexpensive production of biosensors. Disposable biosensors based on screen printed electrodes (SPEs) including microelectrodes and modified electrodes have led to new possibilities in the detection and quantitation of biomolecules, pesticides, antigens, DNA, microorganisms and enzymes. SPE-based sensors are in tune with the growing need for performing rapid and accurate in-situ analyses and for the development of portable devices. This review (with 226 refs.) first gives an introduction into the topic and then is subdivided into sections (a) on DNA sensors (including methods for the detection of hybridization and damage), (b) on aptasensors (for thrombin, OTA, immunoglobulins and cancer biomarkers), (c) on immunosensors (for microorganisms, immunoglobulins, toxins, hormones, lactoferrin and biomarkers), (d) on enzymatic biosensors (for glucose, hydrogen peroxide, various pharmaceuticals, neurotransmitters, amino acids, NADH, enzyme based sensors).

From electronic to opto-electronic biosensors: an engineering view

Electronic engineering has played a significant role in biosensor design, at the primary transducer level, since the appearance of chemically sensitive field-effect transistors (CHEMFETs) in the seventies. The early promise of CHEMFETs could not easily be carried through into more advanced biosensors, e.g., immunosensors, not have CHEMFETs paved the way for a range of non-sensing bioelectronic devices. However, collaboration of electronic engineers and biosensor designers, at a level more fundamental than simple signal-processing instrumentation, was initiated. Such collaborations have led to the appearance of several very promising opto-electronic biosensors and in the use of micro-electronic fabrication techniques in, otherwise, conventional biosensors. It is now possible to foresee the wide use of integrated micro-optical biosensors in medicine and the possibility that integrated fault-tolerant biosensor arrays may start to address some of the severe problems of using biosensors in process control.     

Development and Use of Antibodies in Surface Plasmon Resonance-Based Immunosensors for Environmental Monitoring

The interaction between antibody and antigen is characterised by relatively high affinity and specificity, making this type of reaction a prime candidate for use as an analytical tool. The interaction may be combined with biosensors in the production of immunosensors for environmental monitoring. Polyclonal and monoclonal antibodies have had a significant impact in analytical detection systems over the past few decades with antibody fragments becoming important in recent years. Production of antibodies to small haptens requires the initial conjugation of hapten to a larger carrier molecule. Once hapten-carrier conjugates have been produced, polyclonal, monoclonal and various antibody fragments may be produced by differing protocols. A critical step in the production of antibody fragments is the development of efficient screening procedures to identify suitable antibody-producing clones and this has been reviewed in this article. Various antibody types may then be used in the generation of immunosensors for the monitoring of environmental pollutants. The selection of the appropriate sensor technology applicable for the determination of an antibody-antigen interaction is of prime importance for immunosensor development. One example of such an application is surface plasmon resonance-based biosensors, as they provide real-time analysis of interactions between the antibody and antigen of interest.     

Summary of ISO/TC 201 Technical Report: ISO/TR 19693 Surface chemical analysis—Characterization of functional glass substrates for biosensing applications

ISO/TR 19693:2018—Surface chemical analysis—Characterization of functional glass substrates for biosensing applications gives an overview of methods, strategies, and guidance to identify possible sources of problems related to substrates, device production steps (cleaning, activation, and chemical modification), and shelf life (storage conditions and aging). It is particularly relevant for surface chemical analysts characterizing glass‐based biosensors, and developers or quality managers in the biosensing device production community. Based on quantitative and qualitative surface chemical analysis, strategies for identifying the cause of poor performance during device manufacturing can be developed and implemented. A review of measurement capabilities of surface analytical methods is given to assist readers from the biosensing community.     

Electrochemical Biosensors Based on Layer‐by‐Layer Assemblies

Layer‐by‐layer (LBL) assemblies, which have undergone great progress in the past decades, have been used widely in the construction of electrochemical biosensors. The LBL assemblies provide a strategy to rationally design the properties of immobilized films and enhance the performance of biosensors. The following review focuses on the application of LBL assembly technique on electrochemical enzyme biosensors, immunosensors and DNA sensors.     

Piezoelectric (PZ) Immunosensors and Their Applications

Abstract

The recent development of piezoelectric immunosensors is reviewed. The selectivity provided by the biological coatings together with the inherent sensitivity of the PZ devices and the ability to oscillate the crystal in liquid medium have induced a rising interest in this class of sensors. Methods of coating and several applications are reported including microgravimetric immunoassays, microbial assays and gas phase immunosensors.     

Cysteine‐reactive covalent capture tags for enrichment of cysteine‐containing peptides

Considering the tremendous complexity and the wide dynamic range of protein samples from biological origin and their proteolytic peptide mixtures, proteomics largely requires simplification strategies. One common approach to reduce sample complexity is to target a particular amino acid in proteins or peptides, such as cysteine (Cys), with chemical tags in order to reduce the analysis to a subset of the whole proteome. The present work describes the synthesis and the use of two new cysteinyl tags, so‐called cysteine‐reactive covalent capture tags (C³T), for the isolation of Cys‐containing peptides. These bifunctional molecules were specifically designed to react with cysteines through iodoacetyl and acryloyl moieties and permit efficient selection of the tagged peptides. To do so, a thioproline was chosen as the isolating group to form, after a deprotection/activation step, a thiazolidine with an aldehyde resin by the covalent capture (CC) method. The applicability of the enrichment strategy was demonstrated on small synthetic peptides as well as on peptides derived from digested proteins. Mass spectrometric (MS) analysis and tandem mass spectrometric (MS/MS) sequencing confirmed the efficient and straightforward selection of the cysteine‐containing peptides. The combination of C³T and CC methods provides an effective alternative to reduce sample complexity and access low abundance proteins. Copyright © 2009 John Wiley & Sons, Ltd.     

基于导电聚吡咯生物电化学传感器的研究进展

导电聚合物具有良好的导电性能,可以作为分子导线使电子在生物活性物质与电极间直接传递,是构建生物传感器的一种新型材料.聚吡咯(PPy)具有导电性、生物相容性、易固定等特点,在传感器中用于固定生物活性物质有着良好的应用前景.该文简要介绍了导电聚吡咯的合成方法及掺杂机理,重点评述了聚吡咯用于固定生物活性物质构建生物传感器的多...     

Integrated biosensors: Promises and problems

After a brief review of the biosensors area, this paper explores the possibilities of integrating various classes of biosensors on silicon. Of all classes of sensors, electrochemical and bioelectrochemical sensors are the most suitable for integration, although substantial research on the fabrication and understanding of bioactive layers on semiconductor sensors is still required. Optical, gravimetric and thermal sensors could also be integrated to varying extents; however, the cost benefits are not yet very attractive except for immunosensors based on immobilized immunoglobulins. Electrochemical and gravimetric sensors based on silicon show the greatest potential for batch fabrication and could therefore be best suited for disposable sensors. The review ends with a discussion of the technological, functional and conceptual problems associated with integrated biosensors.     

Immunochemical methods for the detection of sulfanylamide drugs

Recent achievements in the detection of sulfanylamide drugs in environmental objects and foodstuffs are considered. These are the specific detection of individual substances; class-specific immunoassay of the whole group of sulfamide drugs; widely used ELISA methods; biosensors; fluorescence polarization immunoassay; and new promising methods for the detection of sulfamide drugs, immunochromatographic test strips, the method using molecularly imprinted polymers, piezoelectric quartz immunosensors, etc.     

Principles and applications of electrochemical and optical biosensors

The principles of biocatalytic and bioaffinity biosensors are reviewed with emphasis on electron transfer-type enzyme sensors, optical enzyme sensors and optical immunosensors for homogeneous immunoassay. An enzyme sensor for ethanol was fabricated by electrochemical polymerization of pyrrole onto the surface of platinized platinum-adsorbed alcohol dehydrogenase—NAD—Meldola Blue. Ethanol was determined amperometrically by measuring the oxidative current through polypyrrole. An optical enzyme sensor is exemplified by an acethylcholine sensor based on an optical pH fibre sensor using a thin polyaniline film. The optical immunosensor for homogeneous immunoassay consists of an optical fibre, the end of the which is coated with an optically transparent platinum electrode. With using luminol as a label, highly sensitive homogeneous immunoassay is carried out by measuring the electrochemical luminescence of the label.     

Immunoassays for aflatoxins

Immunoassays for aflatoxin analysis have been regarded as valuable supplements to existing and rapidly developing chromatographic techniques. We describe six types of aflatoxin immunogens and their characteristics, reported antibodies against aflatoxins, traditional and novel labeled materials for assay signaling, three immunoassay formats, assay devices (e.g., microtiter plate and reader, lateral flow strip, electronic and optical immunosensors, and a rapid tester dedicated to aflatoxins) and applications of immunoassay in agricultural products. We show trends towards sensitivity, simplification, intelligence and portability. After setting out five challenges in developing immunoassays, we predict that techniques involving novel nanoparticle labels and non-competitive assay may become the main trends in research and that immunoassay devices will be used in many fields.     

Simultaneous Determination of Creatine and Creatinine using Monocrystalline Diamond Paste–Based Amperometric Biosensors

Abstract

In order to determine creatine and creatinine, amperometric diamond paste biosensors were proposed. A bienzymatic biosensor based on creatinase and sarcosine oxidase was used for the assay of creatine and a trienzymatic biosensor based on creatinase, sarcosine oxidase, and creatininase was proposed for the assay of creatinine. The linear concentration ranges are of fmol/L magnitude order, with very low limits of detection. The biosensors proved to be highly reliable for determination of creatine and creatinine as raw materials in pharmaceutical formulations as well as in serum samples.     

Advances in pesticide biosensors: current status, challenges, and future perspectives

Public concern over pesticide residues has been increasing dramatically owing to the high toxicity and bioaccumulation effects of pesticides and the serious risks that they pose to the environment and human health. It is therefore crucial to monitor pesticide residues by using various analytical methods and techniques, especially highly sensitive, highly selective, simple, rapid, cost-effective, and portable ones. Biosensor strategies have become research hotspots and ideal candidates for pesticide detection, having such features as high sensitivity, fast response, robustness, low cost and miniaturization, as well as in situ and real-time monitoring. This review covers advances in the design and fabrication of biosensors for pesticide detection since 2005. Special emphasis is placed on the state-of-art selection of receptors, the use of different transduction techniques and fast screening strategies, and the application of various biosensors developed in food and environmental safety. Both advantages and drawbacks of these techniques are then summarized. Finally, challenges, strategies, and perspectives in further developing pesticide biosensors are also discussed.

A new strategy for the development of monoclonal antibodies for the determination of human procalcitonin in serum samples

Procalcitonin (PCT)—a diagnostic serum parameter for bacterial infection and sepsis—is of great interest in the field of biosensors for point-of-care testing. Its detection needs specific biological recognition elements, such as antibodies. Herein, we describe the development and characterization of rat monoclonal antibodies (mAbs) for PCT, and their application in enzyme-linked immunosorbent assays (ELISAs) for the determination of PCT in patient serum samples. From about 50 mAbs, two mAbs, CALCA 2F3 and CALCA 4A6, were selected as a pair with high affinity for PCT in sandwich immunoassays. Both mAbs could be used either as capture or as detection mAb. They were Protein G-purified and biotinylated when used as detection mAb. The setup of two sandwich ELISAs with standards of human recombinant (hr) PCT, using either CALCA 2F3 (assay A) or CALCA 4A6 (assay B) as capture mAbs and the biotinylated mAbs CALCA 4A6 or CALCA 2F3, respectively, as detection mAbs, led to highly specific determinations of PCT without cross-reactivity to calcitonin and katacalcin. Test midpoints (IC₅₀) of both assays were determined for hrPCT standards in 4% (w/v) human serum albumin and found with 2.5 (assay A) and 2.7 μg L⁻¹ (assay B). With both sandwich ELISAs a collection of eight patient serum samples have been determined in comparison to the determination by the Elecsys BRAHMS PCT assay. Good correlations between our prototype ELISAs and the BRAHMS assay could be demonstrated (R ²: assay A, 0.996 and assay B, 0.990). The use of these newly developed anti-PCT mAbs should find broad applications in immunosensors for point-of-care diagnostics of sepsis and systemic inflammation processes.