Progress of rapid detection of pesticides in fruits and vegetables

Pesticide residues in fruits and vegetables present a significant concern for human health and safety. By 2022, an average of 3 million people worldwide is poisoned by pesticides every year, and the mortality rate can reach about 20%. This comprehensive review summarizes recent research on the detection of pesticide residues, focusing on the main detection methods and their implications. The study highlights the growing importance of biosensors as a prominent technique, offering enhanced efficiency and accuracy in pesticide residue analysis. The review addresses the challenges associated with pretreatment methods and discusses the advantages and limitations of biosensors. Furthermore, it emphasizes the need for further research to optimize the adaptive capabilities of biosensors, particularly their anti-interference abilities. The findings underscore the significance of developing intelligent adaptive sensors for on-site pesticide residue detection, eliminating the need for complex sample pretreatment. This comprehensive review serves as a valuable reference, facilitating future advancements in pesticide residue analysis, ensuring food safety, and safeguarding consumer health in modern agriculture

Naked eye sensors for on-site pesticide detection: a review

Contamination by pesticides is known to be one of the major issues that are enormously degrading the quality of food and fodder crops together with increased agricultural, environmental and aquatic pollution. Many analytical and laboratory methods are available for detection of these pesticides in products in order to maintain food security but these methods are not readily accessible to most people including farmers for on-site and onfield detection in the crops. The development of more convenient, fast, and cost-effective methods that can be easily accessed by laymen based on simple paper strips or mobile analyzers etc. are need of the time. This review includes a brief discussion about novel devices which have been introduced in the field for pesticide detection viz. easy to use colorimetric and non-colorimetric detection methods based on various electrochemical and optical sensing strategies. These techniques exhibited promising results in field of on-site pesticide detection owing to their easy production, high sensitivity and readily accessible results obtained with these portable devices. This review further describes emerging prospects, deficits and challenges associated with the application of the aforementioned sensing devices

Recent Advancements in the Technologies Detecting Food Spoiling Agents

To match the current life-style, there is a huge demand and market for the processed food whose manufacturing requires multiple steps. The mounting demand increases the pressure on the producers and the regulatory bodies to provide sensitive, facile, and cost-effective methods to safeguard consumers’ health. In the multistep process of food processing, there are several chances that the food-spoiling microbes or contaminants could enter the supply chain. In this contest, there is a dire necessity to comprehend, implement, and monitor the levels of contaminants by utilizing various available methods, such as single-cell droplet microfluidic system, DNA biosensor, nanobiosensor, smartphone-based biosensor, aptasensor, and DNA microarray-based methods. The current review focuses on the advancements in these methods for the detection of food-borne contaminants and pathogens

Supramolecular Luminescent Sensors

There is great need for stand-alone luminescence-based chemosensors that exemplify selectivity, sensitivity, and applicability and that overcome the challenges that arise from complex, real-world media. Discussed herein are recent developments toward these goals in the field of supramolecular luminescent chemosensors, including macrocycles, polymers, and nanomaterials. Specific focus is placed on the development of new macrocycle hosts since 2010, coupled with considerations of the underlying principles of supramolecular chemistry as well as analytes of interest and common luminophores. State-of-the-art developments in the fields of polymer and nanomaterial sensors are also examined, and some remaining unsolved challenges in the area of chemosensors are discussed

Metal−Organic Frameworks in Agriculture

The work has been supported by the MOFSEIDON project (PID2019-104228RB-100) funded by MCI/AEI/10.13039/ 501100011033/FEDER “Una manera de hacer Europa”, ESENCE project (RTC2019-007254-5) funded by MCIN/ AEI/10.13039/501100011033), Junta de Andalucía (FQM- 394), and the Multifunctional Metallodrugs in Diagnosis and Therapy Network (MICIU, RED2018-102471-T). P.H. acknowledges the Spanish Ramón y Cajal Programme (grant agreement 2014-15039). S.R. acknowledges the Spanish Juan de la Cierva Incorporación Fellowship (grant agreement no. IJC2019-038894-I) funded by MCIN/AEI/10.13039/ 501100011033. Funding for open access charge: Universidad de Granada/CBUA.Agrochemicals, which are crucial to meet the world food qualitative and quantitative demand, are compounds used to kill pests (insects, fungi, rodents, or unwanted plants). Regrettably, there are some important issues associated with their widespread and extensive use (e.g., contamination, bioaccumulation, and development of pest resistance); thus, a reduced and more controlled use of agrochemicals and thorough detection in food, water, soil, and fields are necessary. In this regard, the development of new functional materials for the efficient application, detection, and removal of agrochemicals is a priority. Metal–organic frameworks (MOFs) with exceptional sorptive, recognition capabilities, and catalytical properties have very recently shown their potential in agriculture. This Review emphasizes the recent advances in the use of MOFs in agriculture through three main views: environmental remediation, controlled agrochemical release, and detection of agrochemicals.MOFSEIDON project (PID2019-104228RB-100) funded by MCI/AEI/10.13039/ 501100011033/FEDERESENCE project (RTC2019-007254-5) funded by MCIN/ AEI/10.13039/501100011033Junta de Andalucía (FQM- 394), and the Multifunctional Metallodrugs in Diagnosis and Therapy Network (MICIU, RED2018-102471-T)Spanish Ramón y Cajal Programme (grant agreement 2014-15039)Spanish Juan de la Cierva Incorporación Fellowship (grant agreement no. IJC2019-038894-I) funded by MCIN/AEI/10.13039/ 501100011033Funding for open access charge: Universidad de Granada/CBU

Carbon-Based Nanomaterials for (Bio)Sensors Development

Carbon-based nanomaterials have been increasingly used in sensors and biosensors design due to their advantageous intrinsic properties, which include, but are not limited to, high electrical and thermal conductivity, chemical stability, optical properties, large specific surface, biocompatibility, and easy functionalization. The most commonly applied carbonaceous nanomaterials are carbon nanotubes (single- or multi-walled nanotubes) and graphene, but promising data have been also reported for (bio)sensors based on carbon quantum dots and nanocomposites, among others. The incorporation of carbon-based nanomaterials, independent of the detection scheme and developed platform type (optical, chemical, and biological, etc.), has a major beneficial effect on the (bio)sensor sensitivity, specificity, and overall performance. As a consequence, carbon-based nanomaterials have been promoting a revolution in the field of (bio)sensors with the development of increasingly sensitive devices. This Special Issue presents original research data and review articles that focus on (experimental or theoretical) advances, challenges, and outlooks concerning the preparation, characterization, and application of carbon-based nanomaterials for (bio)sensor development

Selection and characterization of DNA aptamers for estradiol and ethynylestradiol for aptasensor development

Small organic contaminants have been widely detected in the surface and ground waters of this nation. A sub-class of these contaminants called endocrine disrupting compounds (EDCs) are known to have adverse effects on aquatic and human health. Among the EDCs, natural hormone 17β-estradiol (E2) and synthetic hormone 17α-ethynylestradiol (EE) possess high estrogenic potency and hence are contaminants of interest. Conventional methods to detect these compounds are expensive, time consuming and need implementation by an expert. By contrast, antibody-based assays are relatively inexpensive and commercially available but suffer from poor selectivity. A promising alternative makes use of DNA aptamers as molecular recognition elements. In order to evaluate the potential of DNA aptamers and aptasensors to detect small organics in natural waters, the following objectives were pursued: (1) critically review DNA aptamers and aptasensors developed for small organic molecules and assess their use for monitoring environmentally relevant organics, (2) select and characterize DNA aptamers that bind to E2 and EE and, (3) study the effect of immobilization on the binding affinity of the selected E2 and EE aptamers. A review of ~80 aptamers and ~200 aptasensors for small organics was conducted to identify factors that affect binding affinity of the aptamer and limits of detection (LODs) of the aptasensor. Based on regression analyses, aptamer binding affinities are found to have a weak relationship with hydrophobicity of the target and length of the aptamer (p-values<0.05). Independent t-tests comparing aptasensor LODs suggest that the electrochemical platform is significantly more sensitive than colorimetric and fluorescence-based platforms. The inherent binding affinity of the aptamer was found to have a significant effect on the LOD of the aptasensor. While some fabricated aptasensors are sufficiently sensitive to detect contaminants at environmentally relevant concentrations, they are often associated with complex fabrication steps, and/or interference from structurally similar analogs. As a result, aptasensor commercialization faces many challenges including reusability, reproducibility and robustness. In vitro selections were conducted with different selection pressures to isolate sensitive and selective DNA aptamers for E2 and EE. An equilibrium-filtration assay was used to determine dissociation constants (Kd) of the aptamer towards its parent target and its analogues. The E2 aptamers, E2Apt1 and E2Apt2 were found to have Kd values of 0.6 µM. They bound to analogue estrone (E1) with a similar affinity but were at least 74-fold more selective over EE. The EE aptamers Kd values are 0.5-1 µM. While one EE aptamer (EEApt1) was 53-fold more selective for EE over E2 and E1, the second EE aptamer (EEApt2) bound to all three EDCs (E1, E2 and EE) with similar affinities. The aptamers maintained their binding affinities in natural waters samples (tap water and lake water). DMS probing of the structure of the DNA aptamer revealed that the binding regions were mostly located in the single-stranded loop regions of the aptamer. Aptasensors typically employ immobilized aptamers though the aptamers are selected and characterized while free or unattached in solution. The Kd values of immobilized selective aptamers were evaluated using magnetic microbeads surface for attachment. E2Apt1 immobilized at either end (5′ or 3′) and E2Apt2 immobilized at the 3′ end retain their binding affinity. The binding affinity is inversely correlated to the average linear distance of the binding pocket from the immobilized end. This result suggests that unwanted interactions between the aptamer and other moieties are more likely when the binding pocket is further away from the surface. Binding curve of E2Apt2 immobilized at the 5′ end indicates potential dimerization at high loadings of aptamer on the beads due to increased proximity between aptamer strands. EEApt1 loses its binding affinity upon immobilization potentially due to disruption in its tertiary structure upon attachment to the surface. Despite no loss in binding affinity upon immobilization, E2Apt1 (5′) shows no significant change in electrochemical current on binding to E2 when incorporated into an electrochemical sensor. This result implies an insufficient conformational change of the aptamer on binding to the target. Overall, this work identifies the first aptamers for EE and selective aptamers for E2, while also highlighting the issues with development of aptamers and their eventual incorporation into aptasensors to detect small organics. Two major concerns are (1) immobilizing aptamers in sensor platforms while selections of aptamers are conducted with free/unattached aptamers, resulting in loss of binding affinity and (2) insufficient conformational change of the aptamer on binding to small molecule targets, resulting in a lack of change in the sensor signal. The findings from this dissertation support additional research directions regarding employing free aptamers in sensors and/or conducting new selections for aptamers using a DNA pool that is attached to a surface

Biosensors for Environmental Monitoring

Real-time and reliable detection of molecular compounds and bacteria is essential in modern environmental monitoring. For rapid analyses, biosensing devices combining high selectivity of biomolecular recognition and sensitivity of modern signal-detection technologies offer a promising platform. Biosensors allow rapid on-site detection of pollutants and provide potential for better understanding of the environmental processes, including the fate and transport of contaminants.This book, including 12 chapters from 37 authors, introduces different biosensor-based technologies applied for environmental analyses

Selected Papers from the 1st International Electronic Conference on Biosensors (IECB 2020)

The scope of this Special Issue is to collect some of the contributions to the First International Electronic Conference on Biosensors, which was held to bring together well-known experts currently working in biosensor technologies from around the globe, and to provide an online forum for presenting and discussing new results. The world of biosensors is definitively a versatile and universally applicable one, as demonstrated by the wide range of topics which were addressed at the Conference, such as: bioengineered and biomimetic receptors; microfluidics for biosensing; biosensors for emergency situations; nanotechnologies and nanomaterials for biosensors; intra- and extracellular biosensing; and advanced applications in clinical, environmental, food safety, and cultural heritage fields