Analysis & sensing最新文献

Biosensors are analytical tools that integrate a biological element with a physicochemical detector in order to quantify the existence or concentration of chemicals, biomolecules, or other biological elements for human health monitoring purposes. Electrochemical techniques for biological analyte detection include the use of electrochemical sensors to identify and quantify the existence and concentration of biological molecules. These techniques are often used because of their high sensitivity, specificity, quick reaction time, and the possibility of being made smaller in size, but still, the research problem in electrochemical-based biosensing largely revolves around improving biosensors′ sensitivity, selectivity, stability, and response time. Borophene, an intriguing and novel substance within the domain of two-dimensional (2D) materials, emerges as a highly promising protagonist in the continuous and dynamic history of nanoscience and nanotechnology. Borophene, characterized by its distinctive electronic, mechanical, and thermal properties, enthralls scientists due to its atomic structure consisting exclusively of boron atoms organized in a honeycomb lattice. In recent years, borophene hybrids and composites have emerged as potentially fruitful avenues for expanding their utility in numerous fields and improving their properties. In addition, borophene and its hybrid systems hold significant potential to overcome the limitations of current electrochemical-based biosensors. By leveraging their unique properties—such as high surface area, chemical versatility, and mechanical strength—these materials can improve biosensors′ limitations. Moreover, the integration of borophene with other materials can further optimize performance, paving the way for advanced and practical biosensing solutions. This perspective presents a synopsis of recent developments in biosensing composites and hybrids based on borophene, including polymers and other nanomaterials. In addition, we emphasized the remarkable characteristics of borophene hybrids, which permit the detection of biological analytes such as proteins, nucleic acids, and small molecules in a sensitive and selective manner. Additionally, a summary of the computational investigations into analyte detection utilizing borophene-based systems has been provided. In a nutshell, we discussed the challenges and future directions in the field, outlining opportunities for further innovation and optimization of borophene-based biosensing platforms.

The expression profiles of intracellular biomarkers hold significance for understanding cellular biological functions and tracking pathological activities. Due to its programmability and biocompatibility, extensive efforts have been devoted to design various kinds of nucleic acid probes for biomarker detection. However, pinpointing a single biomarker could end up in a false positive signal, delaying diagnosis. In this review, we present an overview of current advances in biomarker detection and signal amplification techniques. We highlight strategies for biomarker multiplexing and signal amplification with combination of isothermal approaches. High specificity and sensitivity are the two criteria for a desired probe, as are the challenges encountered by a probe that operates efficiently in biological systems. With higher biomarker identification accuracy, we may be able to move one step closer to precision medicine.

Point-of-care diagnostics relies on optical and electrochemical sensors to develop devices that are both compact and cost-effective. Therefore, the search for new design principles for chemosensors that enable multiple signal outputs is a particularly interesting concept. In this work, we present an unimolecular chemosensor based on cucurbit[7]uril that combines two signal readouts - namely fluorescent and electrochemical signals - in a single chemosensor design. This is achieved by utilizing the tunable fluorescence and the electrochemical properties of the reporter molecule, which depend on whether or not it is engulfed by the cucurbit[7]uril cavity in the absence or presence of the analyte. By setting up an assay using the dual readout chemosensor, illicit drug formulations containing pancuronium bromide or nicotine can be detected at low micromolar concentrations (0–100 μM). This assay is compatible with standard fluorescence plate readers and electrochemical devices, including commercially available screen-printed electrodes. Overall, the chemosensor presented in this study represents a significant advance in the development of cucurbit[7]uril chemosensors, characterized by multimodal detection capabilities. It uniquely combines traditional optical and electrochemical detection methods in a single molecular design.

pH is one of the key parameters in chemistry and impacts almost all chemical and biological processes. Also, within analytical chemistry and sensing, pH plays a critical role. This review underscores the critical role of pH manipulation in overcoming analytical challenges posed by complex sample matrices and dynamic environmental conditions. It explores the available tools to control pH at a local scale and how those are or can be applied to improve sensor performance. We focus on four key areas where pH modulation has been or could be leveraged to advance chemical sensing capabilities: i) sensing alkalinity and buffer capacity, ii) sample pretreatment, iii) sensing pH dependent analytes and iv) reducing biofouling. We analyze existing strategies, but also try to identify unexplored possibilities which may have potential and can be exploited for sensing.

Electrochemical immunosensors have emerged in the last years as outstanding analytical systems for the detection of analytes of clinical interest. As alternative to the traditional enzymatic labels, the use of nanoparticles and especially bimetallic ones has gained increased attention thanks to their advantages related to the higher simplicity, stability and sensitivity offered. Main routes for the detection of such nanoparticle labels are based on i) dissolution of the nanoparticle into the corresponding metal ions followed by voltammetric detection; ii) taking advantage of the electrocatalytic effect of the metals towards secondary reactions; and iii) taking advantage of their electrochemiluminescence properties.

Plant hormones and their receptors play a crucial role in regulating plant growth and adapting to the stress environment. The exploration of interaction between plant hormones and their receptors is significant to comprehend the molecular mechanisms of plant growth and development, the response mechanisms of adaptation to environmental changes, and to optimize the traits and stress-resistance of crops. Since the biosynthesis, transport, and metabolism of hormones in plants are closely relevant to spatio-temporal changes, and their content and distribution are highly dynamic, there is an urgent need for a qualitative and quantitative tool to accurately, real-time, and in situ monitor the dynamic changes of hormones in plants without injury. Fluorescent probes have been widely used in the sensing and imaging of plant hormones and their receptors, due to their high spatio-temporal resolution, high selectivity, non-invasive, high sensitivity, and tailored molecular structures. Here, this paper provides a systematical overview of the research progress in the sensing and imaging of plant hormones and their receptors using fluorescent probes. In addition, the potential prospects and remaining challenges are also discussed to design fluorescent probes with better performance and promote the development of this field.

Two-dimensional conductive metal-organic frameworks (MOFs) featuring structural diversity and high porosity represent promising platforms for chemiresistive humidity sensing. The precise control of the structure of lanthanide-based MOFs and an exploration of its impact on charge transport and sensing applications have consistently been focal points for researchers. In this study, we present the synthesis and characterization of Lu-HHTP (HHTP=2,3,6,7,10,11-hexahydroxytriphenylene) as highly crystalline and conductive porous materials. The polymeric framework of Lu-HHTP encompasses 1D hexagonal channels and exhibits interlayer π–π stacking, resulting in a material with a high surface area and uniform rod-like microstructure. Benefiting from its elevated electrical conductivity, the Lu-HHTP-based humidity sensor exhibited commendable sensing properties within the relative humidity range of 33 % to 95 % at room temperature (25 °C), achieving a response value as high as 19 at 95 % relative humidity. Furthermore, the sensor displayed superior repeatability, characterized by rapid response and recovery speeds in the presence of moisture. These findings indicate that Lu-HHTP holds substantial promise as a material for humidity sensors.

Inspired by the powerful biological olfaction, scientists extracted numerous materials such as olfactory sensory neuron, olfactory receptor (OR) protein, and odorant binding protein from animal olfactory systems, then combined them with transducers to form multiple odor biosensors. These biosensors, despite well inheriting the sensing ability of creatures, have several drawbacks, such as complex preparation process, unstable sensing material characteristics, and high cost. Unlike the biological materials listed above, cell expressing heterologous OR maintains a stable sensing performance after passaging for multiple generations, also its experimental operation is simple, and cost is low. Therefore, odor biosensors based on cell expressing OR have been well developed in recent years. In this review, we first listed several odor biosensors based on cell expressing OR, mainly focusing on fluorescent and electrophysiological measurement methods. Furthermore, we illustrated the techniques to improve the biosensor performance, e. g., wider detection range, longer lifetime, more OR types, and higher quantification efficiency. In addition, we explained the possible prospects such as big sensor array and predicting odor response.