Recent achievements and advances in optical and electrochemical aptasensing detection of ATP based on quantum dots

CRISPR/Cas12a trans-cleavage mediated photoelectrochemical biosensor based on zeolitic imidazolate framework-67 for ATP determination

An efficient PEC biosensor is proposed for ATP detection based on exciton energy transfer from CdTe quantum dots (CdTe QDs) to Au nanoparticles (AuNPs), integrating CRISPR/Cas12a trans-cleavage activity and specific recognition of ZIF-67 to ATP. Exciton energy transfer between CdTe QDs and AuNPs system is firstly constructed as photoelectrochemical (PEC) sensing substrate. Then, the activator DNAs, used to activate CRISPR/Cas12a, are absorbed on the surface of ZIF-67. In the presence of ATP, the activator DNAs are released due to more efficient adsorption of ZIF-67 to ATP. The released activator DNA activates trans-cleavage activity of CRISPR/Cas12a to degrade ssDNA on the electrode, leading to the recovery of photocurrent due to the interrupted energy transfer. Benefiting from the specific recognition of ZIF-67 to ATP and CRISPR/Cas12a-modulated amplification strategy, the sensor is endowed with excellent specificity and high sensitivity.

Recent Advances in Aptasensors for Rapid Pesticide Residues Detection

Pesticides are applied widely to increase agricultural output and quality, however, this practice results in residual issues that not only harm the environment but also put people and animals' lives and health at risk. As a result, it is critical to find pesticide residues in a variety of sources, including crops, water supplies, and soil. Aptamers are more flexible in their synthesis and modification, have a high level of specificity, are inexpensive, and have good stability compared to conventional detection methods. They have therefore attracted a lot of interest in the industry. This study reviews the most recent aptasensor advancements in the detection of pesticide residues. Firstly, aptamers specifically binding to many pesticides are summarized. Secondly, the combination of aptasensors with colorimetric, fluorescent, surface enhanced Raman spectroscopy (SERS), resonance Light Scattering (RLS), chemiluminescence (CL), electrochemical, and electrochemiluminescence (ECL) technologies are systematically introduced, and their advantages and disadvantages are expounded. Importantly, the aptasensors for the detection of various pesticides (organochlorine, organophosphorus, neonicotinoids, carbamates, and pyrethroids) that have been developed so far are systematically analyzed and discussed. Finally, the furture prospects and challenges of the aptasensors are highlighted. It is expected to offer suggestions for the later creation of novel, highly effective and sensitive aptasensors for the detection of pesticide residues.

High-throughput and specific detection of microorganisms by intelligent modular fluorescent photoelectric microbe detector

Food safety has emerged as a major global issue. Detecting foodborne pathogenic microorganisms and controlling them is vital to guard against foodborne diseases caused by microorganisms. However, the current detection methods need to meet the demand for real-time detection on the spot after a simple operation. Considering unresolved challenges, we developed an Intelligent Modular Fluorescent Photoelectric Microbe (IMFP) system containing a special detection reagent. This IMFP system can automatically monitor microbial growth in which the photoelectric detection, temperature control, fluorescent probe, and bioinformatics screen are integrated into one platform and employed to detect pathogenic microorganisms. Moreover, a specific culture medium was also developed, which matched the system platform for Coliform bacteria and Salmonella typhi. The developed IMFP system could attain a limit of detection (LOD) of about 1 CFU/mL for both bacteria, while the selectivity could reach 99%. In addition, the IMFP system was applied to detect 256 bacterial samples simultaneously. This platform reflects the high-throughput needs of fields for microbial identification and related requirements, such as the development of pathogenic microbial diagnostic reagents, antibacterial sterilization performance tests, and microbial growth kinetics. The IMFP system also confirmed the other merits, such as high sensitivity, high-throughput, and operation simplicity compared to conventional methods, and it has a high potential as a tool for application in the health and food security fields.

Advances in electrochemiluminescence for single-cell analysis

Recent years have witnessed the emergence of innovative analytical methods with high sensitivity and spatiotemporal resolution that allowed qualitative and quantitative analysis to be carried out at single-cell and subcellular levels. Electrochemiluminescence (ECL) is a unique chemiluminescence of high-energy electron transfer triggered by electrical excitation. The ingenious combination of electrochemistry and chemiluminescence results in the distinct advantages of high sensitivity, a wide dynamic range and good reproducibility. Specifically, single-cell ECL (SCECL) analysis with excellent spatiotemporal resolution has emerged as a promising toolbox in bioanalysis for revealing individual cells' heterogeneity and stochastic processes. This review focuses on advances in SCECL analysis and bioimaging. The history and recent advances in ECL probes and strategies for system design are briefly reviewed. Subsequently, the latest advances in representative SCECL analysis techniques for bioassays, bioimaging and therapeutics are also highlighted. Then, the current challenges and future perspectives are discussed.

Stimulus-Responsive Metal-Organic Framework Signal-Reporting System for Photoelectrochemical and Fluorescent Dual-Mode Detection of ATP

Dual-mode bioanalysis integrating photoelectrochemical (PEC) and other modes is emerging and allows signal cross-checking for more reliable results. Metal-organic frameworks (MOFs) have been shown to be attractive materials in various biological applications. This work presents the utilization of MOF encapsulation and stimuli-responsive decapsulation for dual-mode PEC and fluorescence (FL) bioanalysis. Photoactive dye methylene violet (MV) was encapsulated in zeolitic imidazolate framework-90 (ZIF-90) to form an MV@ZIF-90 hybrid material, and MV could be released by adenosine triphosphate (ATP)-induced ZIF-90 disintegration. The released MV not only had FL emission but also had a sensitization effect on the ZnIn₂S₄ (ZnInS) photoanode. Based on the MV-dependent sensitization effect and FL emission characteristic, a dual-mode PEC-FL strategy was established for ATP detection with low detection limits, that is, 3.2 and 4.1 pM for PEC and FL detection, respectively. This study features and will inspire the construction and implementation of smart MOF materials for dual-mode bioanalysis.

Allosteric probe initiated triple signal recycles for sensitive analysis of adenosine triphosphate (ATP)

Adenosine triphosphate (ATP) is closely associated with a variety of pathophysiological process, providing energy for cell activities. However, it remains a huge challenge to develop a simple and sensitive ATP detection method. Herein, we describe an ultrasensitive approach for ATP detection by using an elegantly designed allosteric probe to bind with targets and to induce DNAzyme assisted triple signal recycles. To establish the approach, the allosteric probe is designed with three functional parts to bind with target ATP, to induce signal recycles and to assist chain extension. After recognition of ATP by allosteric probe, the triple signal recycles are initiated, including (i) released ATP-allosteric probe complex unfolds H1 probe, constituting the first signal recycle; (ii) DNAzyme based cleavage induces the second signal recycle; and (iii) chain extension induced release of ATP is the third signal recycle. Through a series of experiments, the approach exhibits a favorable ATP detection performance and shows a high anti-interference ability, indicating a potential application value in early diagnosis of diseases.

Advances in chilling injury of postharvest fruit and vegetable: Extracellular ATP aspects

Due to the global use of cold chain, the development of postharvest technology to reduce chilling injury (CI) in postharvest fruits and vegetables during storage and transport is needed urgently. Considerable evidence shows that maintaining intracellular adenosine triphosphate (iATP) in harvested fruits and vegetables is beneficial to inhibiting CI occurrence. Extracellular ATP (eATP) is a damage-associated signal molecule and plays an important role in CI of postharvest fruits and vegetables through its receptor and subsequent signal transduction under low-temperature stress. The development of new aptasensors for the simultaneous determination of eATP level allows for better understanding of the roles of eATP in a myriad of responses mediated by low-temperature stress in relation to the chilling tolerance of postharvest fruits and vegetables. The multiple biological functions of eATP and its receptors in postharvest fruits and vegetables were attributed to interactions with reactive oxygen species (ROS) and nitric oxide (NO) in coordination with phytohormones and other signaling molecules via downstream physiological activities. The complicated interconnection among eATP in relation to its receptors, eATP/iATP homeostasis, ROS, NO, and heat shock proteins triggered by eATP recognition has been emphasized. This paper reviews recent advances in the beneficial effects of energy handling, outlines the production and homeostasis of eATP, discusses the possible mechanism of eATP and its receptors in chilling tolerance, and provides future research directions for CI in postharvest fruits and vegetables during low-temperature storage.