新型纳米传感薄膜材料在发酵组分检测中的研究进展

发酵工业目前缺少组分浓度实时监控技术以实现精确过程调控，因此，发酵用生物传感器逐渐受到该领域的重视。本文将关注发酵用生物传感器的最新研究进展，特别综述新型纳米传感材料在发酵组分检测中的最新研究成果，介绍在不同的发酵体系中纳米材料的设计及合成策略，包括贵金属、金属氧化物、配位化合物、有机化合物及碳基等各类纳米材料，简述这些纳米材料在发酵传感中的检测机理以及所开发的生物传感器在不同真实发酵液中的检测性能，从检测灵敏度、工作电位、抗干扰能力等方面系统地评价各类纳米材料在发酵环境中使用的优势和不足，分析发酵体系专用生物传感器材料的发展方向，为研发出可实现“多组分”及“宽检测范围”的发酵组分浓度检测技术提供重要的参考及借鉴。     

Nanomaterials Used in Fluorescence Polarization Based Biosensors

Fluorescence polarization (FP) has been applied in detecting chemicals and biomolecules for early-stage diagnosis, food safety analyses, and environmental monitoring. Compared to organic dyes, inorganic nanomaterials such as quantum dots have special fluorescence properties that can enhance the photostability of FP-based biosensing. In addition, nanomaterials, such as metallic nanoparticles, can be used as signal amplifiers to increase fluorescence polarization. In this review paper, different types of nanomaterials used in in FP-based biosensors have been reviewed. The role of each type of nanomaterial, acting as a fluorescent element and/or the signal amplifier, has been discussed. In addition, the advantages of FP-based biosensing systems have been discussed and compared with other fluorescence-based techniques. The integration of nanomaterials and FP techniques allows biosensors to quickly detect analytes in a sensitive and cost-effective manner and positively impact a variety of different fields including early-stage diagnoses.     

Development of an electrochemical‐surface plasmon dual biosensor based on carboxylated conducting polymer thin films

A biosensing platform based on the covalent attachment of biomolecules on electropolymerized carboxylated conducting polymers, poly(3‐aminobenzoic acid) and poly(3‐pyrrole carboxylic acid), were developed for the selective simultaneous detection of two biomolecules using electrochemical‐surface plasmon resonance (EC–SPR) spectroscopy. The surface morphology of the developed biosensors was studied by scanning electron microscopy and atomic force microscopy. The EC–SPR dual biosensor was developed for the label‐free, simultaneous, and selective detection of glucose and human immunoglobulin G (IgG). A change in current density was clearly observed after the injection of glucose, whereas a change in SPR reflectivity was clearly observed after the injection of human IgG. The present work demonstrates the potential of this biosensing platform for real sample analysis in the future. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45641.     

Simple fabrication of functionalized surface with polyethylene glycol microstructure and glycidyl methacrylate moiety for the selective immobilization of proteins and cells

This study reported simple surface modification for the immobilization of biomolecules such as proteins and cells onto desired area at micron-scale level. First, thin film composed of glycidyl methacrylate (GMA) was prepared by UV-photopolymerization. Then, the polyethylene glycol (PEG) microstructures which played a role in the prevention of nonspecific binding of biomolecules were fabricated by using micromolding in capillaries (MIMIC). Thus, we could easily obtain an orthogonal surface having biomolecular attraction and repulsion areas. In addition, we could control of the height of prepared PEG microstructures with spin coating or not. For the investigation of feasibility of biomolecule patterning onto the functionalized surface, FITC-BSA and HEK 293 were examined as representative biomolecule models. A functionalized surface with GMA promotes the strong adhesion of biomolecules, and PEG microstructures located on the background prevent nonspecific binding of biomolecules at micron-scale level. The orthogonal difference in surface functionality showed strong possibility of simple patterning of biomolecules. In addition, the proposed method could easily control the size, shape, and height of patterns. It will be useful platform technology for the construction of a biomolecule array.     

Gold nanoparticle-based electrochemical biosensors

The unique properties of gold nanoparticles to provide a suitable microenvironment for biomolecules immobilization retaining their biological activity, and to facilitate electron transfer between the immobilized proteins and electrode surfaces, have led to an intensive use of this nanomaterial for the construction of electrochemical biosensors with enhanced analytical performance with respect to other biosensor designs. Recent advances in this field are reviewed in this article. The advantageous operational characteristics of the biosensing devices designed making use of gold nanoparticles are highlighted with respect to non-nanostructured biosensors and some illustrative examples are commented. Electrochemical enzyme biosensors including those using hybrid materials with carbon nanotubes and polymers, sol-gel matrices, and layer-by-layer architectures are considered. Moreover, electrochemical immunosensors in which gold nanoparticles play a crucial role in the electrode transduction enhancement of the affinity reaction as well as in the efficiency of immunoreagents immobilization in a stable mode are reviewed. Similarly, recent advances in the development of DNA biosensors using gold nanoparticles to improve DNA immobilization on electrode surfaces and as suitable labels to improve detection of hybridization events are considered. Finally, other biosensors designed with gold nanoparticles oriented to electrically contact redox enzymes to electrodes by a reconstitution process and to the study of direct electron transfer between redox proteins and electrode surfaces have also been treated.     

核酸探针在抗生素残留生物传感检测中的应用

抗生素作为动物治疗剂和生长促进剂广泛应用于农业、畜牧业、水产品养殖业,导致动植物食品中抗生素残留量超标,严重威胁人体健康。因此,检测食品中抗生素残留具有重要意义。而现有的抗生素残留检测方法如微生物法、免疫学分析、液相色谱-质谱法、毛细管电泳等,通常具有耗时长、操作复杂、成本高等缺点。生物传感器作为一种高新技术,具有快速简单、灵敏度高、选择性好、成本低等特点,在抗生素残留检测领域具有较大优势。核酸探针作为一种新型生物分析工具广泛应用于生物传感器的开发中,将其引入抗生素残留的生物传感检测为实现抗生素残留的高效检测开辟了新途径。该文从电化学生物传感器、荧光生物传感器、比色生物传感器以及其他常见生物传感器方面综述了核酸探针在抗生素残留生物传感检测中的应用研究进展,并展望了该领域未来的发展前景。     

核酸探针在抗生素残留生物传感检测中的应用

抗生素作为动物治疗剂和生长促进剂广泛应用于农业、畜牧业、水产品养殖业，导致动植物食品中抗生素残留量超标，严重威胁人体健康。因此，检测食品中抗生素残留具有重要意义。而现有的抗生素残留检测方法如微生物法、免疫学分析、液相色谱-质谱法、毛细管电泳等，通常具有耗时长、操作复杂、成本高等缺点。生物传感器作为一种高新技术，具有快速简单、灵敏度高、选择性好、成本低等特点，在抗生素残留检测领域具有较大优势。核酸探针作为一种新型生物分析工具广泛应用于生物传感器的开发中，将其引入抗生素残留的生物传感检测为实现抗生素残留的高效检测开辟了新途径。该文从电化学生物传感器、荧光生物传感器、比色生物传感器以及其他常见生物传感器方面综述了核酸探针在抗生素残留生物传感检测中的应用研究进展，并展望了该领域未来的发展前景。     

Detection of Human Neutrophil Elastase by Fluorescent Peptide Sensors Conjugated to TEMPO-Oxidized Nanofibrillated Cellulose

Peptide–cellulose conjugates designed for use as optical protease sensors have gained interest for point-of-care (POC) detection. Elevated serine protease levels are often found in patients with chronic illnesses, necessitating optimal biosensor design for POC assessment. Nanocellulose provides a platform for protease sensors as a transducer surface, and the employment of nanocellulose in this capacity combines its biocompatibility and high specific surface area properties to confer sensitive detection of dilute biomarkers. However, a basic understanding of the spatiotemporal relationships of the transducer surface and sensor disposition is needed to improve protease sensor design and development. Here, we examine a tripeptide, fluorogenic elastase biosensor attached to TEMPO-oxidized nanofibrillated cellulose via a polyethylene glycol linker. The synthetic conjugate was found to be active in the presence of human neutrophil elastase at levels comparable to other cellulose-based biosensors. Computational models examined the relationship of the sensor molecule to the transducer surface. The results illustrate differences in two crystallite transducer surfaces ((110) vs. (1−10)) and reveal preferred orientations of the sensor. Finally, a determination of the relative (110) vs. (1−10) orientations of crystals extracted from cotton demonstrates a preference for the (1−10) conformer. This model study potentiates the HNE sensor results for enhanced sensor activity design.     

Comparative study of a Surface Plasmon Resonance Biosensor based on Metamaterial and Graphene

In this study, a surface plasmon resonance biosensor at near infrared frequency based on a metamaterial is proposed. The proposed biosensor utilizes the properties of plasmons and metamaterial for enhancement of its performance parameters i.e. sensitivity, detection accuracy and quality factor. The thickness of the metamaterial and gold film has been optimized for optimal performance of the proposed biosensor at near infrared wavelengths. Results obtained from the proposed biosensor were compared with existing two-dimensional nanomaterials such as a graphene based biosensor and a conventional surface plasmon resonance biosensor. Finally, it is observed that the performance parameters of the proposed biosensor are very high when compared to existing surface plasmon resonance biosensors.     

An algorithm for three-dimensional Monte-Carlo simulation of charge distribution at biofunctionalized surfaces

In this work, a Monte-Carlo algorithm in the constant-voltage ensemble for the calculation of 3d charge concentrations at charged surfaces functionalized with biomolecules is presented. The motivation for this work is the theoretical understanding of biofunctionalized surfaces in nanowire field-effect biosensors (BioFETs). This work provides the simulation capability for the boundary layer that is crucial in the detection mechanism of these sensors; slight changes in the charge concentration in the boundary layer upon binding of analyte molecules modulate the conductance of nanowire transducers. The simulation of biofunctionalized surfaces poses special requirements on the Monte-Carlo simulations and these are addressed by the algorithm. The constant-voltage ensemble enables us to include the right boundary conditions; the dna strands can be rotated with respect to the surface; and several molecules can be placed in a single simulation box to achieve good statistics in the case of low ionic concentrations relevant in experiments. Simulation results are presented for the leading example of surfaces functionalized with pna and with single- and double-stranded dna in a sodium-chloride electrolyte. These quantitative results make it possible to quantify the screening of the biomolecule charge due to the counter-ions around the biomolecules and the electrical double layer. The resulting concentration profiles show a three-layer structure and non-trivial interactions between the electric double layer and the counter-ions. The numerical results are also important as a reference for the development of simpler screening models.     

Recent developments and applications of bioinspired silicification

Bioinspired synthesis of silica has attracted attention from a wide range of researchers as novel route for fabrication of various nanomaterials. Proteins including silaffins and silicateins as well as polyamines from marine diatoms and sponges are key biomolecules in these biomimetic silicification processes. These methods allow silica mineralization from various silica precursors under mild, biologically compatible conditions in an unprecedentedly fast and facile manner. Notably, the silica polycondensation entails the concomitant encapsulation of other molecules in the reaction solutions. Due to the efficient encapsulation and synergetic effects brought by the encapsulated molecules and the characteristics of biomimetic silica synthesis as well as the mechanical and chemical properties of silica itself, the silica- biomolecule nanocomposites have broad applications in biocatalysis, biosensor, and biomedical areas. Introduction and combination of novel template, precursors, inorganics, or enzymes with the previously used strategies will allow construction of more efficient, purpose-optimized silica nanomaterials with controlled size, composition, and morphology.     

Facile direct electron transfer in glucose oxidase modified electrodes

Glucose oxidase (GOx) is widely used in the glucose biosensor industry. However, mediatorless direct electron transfer (DET) from GOx to electrode surfaces is very slow. Recently, mediatorless DET has been reported via the incorporation of nanomaterials such as carbon nanotubes and nanoparticles in the modification of electrodes. Here we report GOx electrodes showing DET without the need for any nanomaterials. The enzyme after immobilization with poly-l-lysine (PLL) and Nafion^® retains the biocatalytic activities and oxidizes glucose efficiently. The amperometric response of Nafion-PLL-GOx modified electrode is linearly proportional to the concentration of glucose up to 10 mM with a sensitivity of 0.75 μA/mM at a low detection potential (−0.460 V vs. Ag/AgCl). The methodology developed in this study will have impact on glucose biosensors and biofuel cells and may potentially simplify enzyme immobilization in other biosensing systems.     

Challenges for nanomechanical sensors in biological detection

Nanomechanical biosensing relies on changes in the movement and deformation of micro- and nanoscale objects when they interact with biomolecules and other biological targets. This field of research has provided ever-increasing records in the sensitivity of label-free detection but it has not yet been established as a practical alternative for biological detection. We analyze here the latest advancements in the field, along with the challenges remaining for nanomechanical biosensors to become a commonly used tool in biology and biochemistry laboratories.     

Optical Biosensor Based on Graphene and Its Derivatives for Detecting Biomolecules

Graphene and its derivatives show great potential for biosensing due to their extraordinary optical, electrical and physical properties. In particular, graphene and its derivatives have excellent optical properties such as broadband and tunable absorption, fluorescence bursts, and strong polarization-related effects. Optical biosensors based on graphene and its derivatives make nondestructive detection of biomolecules possible. The focus of this paper is to review the preparation of graphene and its derivatives, as well as recent advances in optical biosensors based on graphene and its derivatives. The working principle of face plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), fluorescence resonance energy transfer (FRET) and colorimetric sensors are summarized, and the advantages and disadvantages of graphene and its derivatives applicable to various types of sensors are analyzed, and the methods of surface functionalization of graphene and its derivatives are introduced; these optical biosensors can be used for the detection of a range of biomolecules such as single cells, cellular secretions, proteins, nucleic acids, and antigen-antibodies; these new high-performance optical sensors are capable of detecting changes in surface structure and biomolecular interactions with the advantages of ultra-fast detection, high sensitivity, label-free, specific recognition, and the ability to respond in real-time. Problems in the current stage of application are discussed, as well as future prospects for graphene and its biosensors. Achieving the applicability, reusability and low cost of novel optical biosensors for a variety of complex environments and achieving scale-up production, which still faces serious challenges.     

纳米管固定化生物分子及其应用

综述了纳米管固定化生物分子的几种主要方法,如交联法、吸附法、包埋法等,并简要地介绍了纳米管固定化生物分子在生物传感、生物催化和生物分离等领域的应用。     

Development of Two-Dimensional Nanomaterials Based Electrochemical Biosensors on Enhancing the Analysis of Food Toxicants

In recent times, food safety has become a topic of debate as the foodborne diseases triggered by chemical and biological contaminants affect human health and the food industry’s profits. Though conventional analytical instrumentation-based food sensors are available, the consumers did not appreciate them because of the drawbacks of complexity, greater number of analysis steps, expensive enzymes, and lack of portability. Hence, designing easy-to-use tests for the rapid analysis of food contaminants has become essential in the food industry. Under this context, electrochemical biosensors have received attention among researchers as they bear the advantages of operational simplicity, portability, stability, easy miniaturization, and low cost. Two-dimensional (2D) nanomaterials have a larger surface area to volume compared to other dimensional nanomaterials. Hence, researchers nowadays are inclined to develop 2D nanomaterials-based electrochemical biosensors to significantly improve the sensor’s sensitivity, selectivity, and reproducibility while measuring the food toxicants. In the present review, we compile the contribution of 2D nanomaterials in electrochemical biosensors to test the food toxicants and discuss the future directions in the field. Further, we describe the types of food toxicity, methodologies quantifying food analytes, how the electrochemical food sensor works, and the general biomedical properties of 2D nanomaterials.     

On the Use of Surface Plasmon Resonance Biosensing to Understand IgG-FcγR Interactions

Surface plasmon resonance (SPR)-based optical biosensors offer real-time and label-free analysis of protein interactions, which has extensively contributed to the discovery and development of therapeutic monoclonal antibodies (mAbs). As the biopharmaceutical market for these biologics and their biosimilars is rapidly growing, the role of SPR biosensors in drug discovery and quality assessment is becoming increasingly prominent. One of the critical quality attributes of mAbs is the N-glycosylation of their Fc region. Other than providing stability to the antibody, the Fc N-glycosylation influences immunoglobulin G (IgG) interactions with the Fcγ receptors (FcγRs), modulating the immune response. Over the past two decades, several studies have relied on SPR-based assays to characterize the influence of N-glycosylation upon the IgG-FcγR interactions. While these studies have unveiled key information, many conclusions are still debated in the literature. These discrepancies can be, in part, attributed to the design of the reported SPR-based assays as well as the methodology applied to SPR data analysis. In fact, the SPR biosensor best practices have evolved over the years, and several biases have been pointed out in the development of experimental SPR protocols. In parallel, newly developed algorithms and data analysis methods now allow taking into consideration complex biomolecular kinetics. In this review, we detail the use of different SPR biosensing approaches for characterizing the IgG-FcγR interactions, highlighting their merit and inherent experimental complexity. Furthermore, we review the latest SPR-derived conclusions on the influence of the N-glycosylation upon the IgG-FcγR interactions and underline the differences and similarities across the literature. Finally, we explore new avenues taking advantage of novel computational analysis of SPR results as well as the latest strategies to control the glycoprofile of mAbs during production, which could lead to a better understanding and modelling of the IgG-FcγRs interactions.     

Moving Average-Based Multitasking In Silico Classification Modeling: Where Do We Stand and What Is Next?

Conventional in silico modeling is often viewed as ‘one-target’ or ‘single-task’ computer-aided modeling since it mainly relies on forecasting an endpoint of interest from similar input data. Multitasking or multitarget in silico modeling, in contrast, embraces a set of computational techniques that efficiently integrate multiple types of input data for setting up unique in silico models able to predict the outcome(s) relating to various experimental and/or theoretical conditions. The latter, specifically, based upon the Box–Jenkins moving average approach, has been applied in the last decade to several research fields including drug and materials design, environmental sciences, and nanotechnology. The present review discusses the current status of multitasking computer-aided modeling efforts, meanwhile describing both the existing challenges and future opportunities of its underlying techniques. Some important applications are also discussed to exemplify the ability of multitasking modeling in deriving holistic and reliable in silico classification-based models as well as in designing new chemical entities, either through fragment-based design or virtual screening. Focus will also be given to some software recently developed to automate and accelerate such types of modeling. Overall, this review may serve as a guideline for researchers to grasp the scope of multitasking computer-aided modeling as a promising in silico tool.     

Pyrene-adamantane-β-cyclodextrin: An efficient host–guest system for the biofunctionalization of SWCNT electrodes

The design of nanostructured biological architectures based on host–guest interactions between β-cyclodextrin and adamantane was investigated on SWCNT coatings using glucose oxidase (GOX) as biomolecule model. β-Cyclodextrin tagged GOX was immobilized on adamantane functionalized carbon nanotubes, deposited on platinum electrodes. Different functionalization techniques to attach “pyrene adamantane” on nanotubes were studied and compared in terms of the performances of the subsequently constructed glucose biosensors. The best results were obtained by dipping the nanotube deposit into a pyrene-adamantane solution followed by electropolymerization of the adsorbed pyrene monolayer. The constructed biosensor exhibited a good linear response toward glucose concentrations between 2 × 10⁻⁷ M and 1.6 × 10⁻³ M. The maximum current density and glucose sensitivity were 154.9 μA cm⁻² and 14.4 mA M⁻¹ cm⁻², respectively.     

Large current difference in Au-coated vertical silicon nanowire electrode array with functionalization of peptides

Au-coated vertical silicon nanowire electrode array (VSNEA) was fabricated using a combination of bottom-up and top-down approaches by chemical vapor deposition and complementary metal-oxide-semiconductor process for biomolecule sensing. To verify the feasibility for the detection of biomolecules, Au-coated VSNEA was functionalized using peptides having a fluorescent probe. Cyclic voltammograms of the peptide-functionalized Au-coated VSNEA show a steady-state electrochemical current behavior. Because of the critically small dimension and vertically aligned nature of VSNEA, the current density of Au-coated VSNEA was dramatically higher than that of Au film electrodes. Au-coated VSNEA further showed a large current difference with and without peptides that was nine times more than that of Au film electrodes. These results indicate that Au-coated VSENA is highly effective device to detect peptides compared to conventional thin-film electrodes. Au-coated VSNEA can also be used as a divergent biosensor platform in many applications.