Multiplexed electrochemical aptasensor for antibiotics detection using metallic-encoded apoferritin probes and double stirring bars-assisted target recycling for signal amplification

A multi-modal biosensing platform based on Ag-ZnIn2S4@Ag-Pt nanosignal probe-sensitized UiO-66 for ultra-sensitive detection of penicillin

We designed a multi-modal biosensing platform for versatile detection of penicillin based on a unique Ag-ZnIn2S4@Ag-Pt signal probe-sensitized UiO-66 metal-organic framework. Firstly, a large number of Ag-ZnIn2S4 quantum dots (AZIS QDs) were attached to Ag-Pt NPs, preparing a new multi-signal probe AZIS QDs@Ag-Pt NPs with excellent photoelectrochemistry (PEC), electrochemiluminescence (ECL), and fluorescence (FL) signals. Moreover, the AZIS QDs@Ag-Pt NPs signal probe can well match the energy level of UiO-66 metal-organic framework (MOF) with good photoelectric property, which can reverse the PEC current of UiO-66 to reduce false positives in detection. When penicillin was present, it bound to its aptamer to release the multifunctional signal probes, which can generate PEC, ECL, and PL signals, thus realizing ultrasensitive detection of penicillin by multi-signals. This work creates a novel three-signal QDs probe, which makes a great contribution to multi-mode photoelectric sensing analysis. The LOD of this work (3.48 fg·mL-1) was much lower than the MRLs (Maximum Residue Levels) established by the EU (4 ng·mL-1). The newly developed multi-mode biosensor has good practical application values in various biological detection, food assay, and early disease diagnosis.

Recent Advances of Biosensors for Detection of Multiple Antibiotics

The abuse of antibiotics has caused a serious threat to human life and health. It is urgent to develop sensors that can detect multiple antibiotics quickly and efficiently. Biosensors are widely used in the field of antibiotic detection because of their high specificity. Advanced artificial intelligence/machine learning algorithms have allowed for remarkable achievements in image analysis and face recognition, but have not yet been widely used in the field of biosensors. Herein, this paper reviews the biosensors that have been widely used in the simultaneous detection of multiple antibiotics based on different detection mechanisms and biorecognition elements in recent years, and compares and analyzes their characteristics and specific applications. In particular, this review summarizes some AI/ML algorithms with excellent performance in the field of antibiotic detection, and which provide a platform for the intelligence of sensors and terminal apps portability. Furthermore, this review gives a short review of biosensors for the detection of multiple antibiotics.

Electrochemical Aptasensors for Antibiotics Detection: Recent Achievements and Applications for Monitoring Food Safety

Antibiotics are often used in human and veterinary medicine for the treatment of bacterial diseases. However, extensive use of antibiotics in agriculture can result in the contamination of common food staples such as milk. Consumption of contaminated products can cause serious illness and a rise in antibiotic resistance. Conventional methods of antibiotics detection such are microbiological assays chromatographic and mass spectroscopy methods are sensitive; however, they require qualified personnel, expensive instruments, and sample pretreatment. Biosensor technology can overcome these drawbacks. This review is focused on the recent achievements in the electrochemical biosensors based on nucleic acid aptamers for antibiotic detection. A brief explanation of conventional methods of antibiotic detection is also provided. The methods of the aptamer selection are explained, together with the approach used for the improvement of aptamer affinity by post-SELEX modification and computer modeling. The substantial focus of this review is on the explanation of the principles of the electrochemical detection of antibiotics by aptasensors and on recent achievements in the development of electrochemical aptasensors. The current trends and problems in practical applications of aptasensors are also discussed.

Advances in Design Strategies of Multiplex Electrochemical Aptasensors

In recent years, the need for simple, fast, and economical detection of food and environmental contaminants, and the necessity to monitor biomarkers of different diseases have considerably accelerated the development of biosensor technology. However, designing biosensors capable of simultaneous determination of two or more analytes in a single measurement, for example on a single working electrode in single solution, is still a great challenge. On the other hand, such analysis offers many advantages compared to single analyte tests, such as cost per test, labor, throughput, and convenience. Because of the high sensitivity and scalability of the electrochemical detection systems on the one hand and the specificity of aptamers on the other, the electrochemical aptasensors are considered to be highly effective devices for simultaneous detection of multiple-target analytes. In this review, we describe and evaluate multi-label approaches based on (1) metal quantum dots and metal ions, (2) redox labels, and (3) enzyme labels. We focus on recently developed strategies for multiplex sensing using electrochemical aptasensors. Furthermore, we emphasize the use of different nanomaterials in the construction of these aptasensors. Based on examples from the existing literature, we highlight recent applications of multiplexed detection platforms in clinical diagnostics, food control, and environmental monitoring. Finally, we discuss the advantages and disadvantages of the aptasensors developed so far, and debate possible challenges and prospects.

Multiply-amplified strategy for the ultrasensitive detection of kanamycin via aptamer-triggered three-dimensional G-quadruplex/Ni-Fe layered double oxide frame networks

In this work, a multiply-amplified peroxidase-like colorimetric strategy was proposed for the high-specific recognition and ultrasensitive detection of kanamycin (Kana). Based on two Kana-aptamer triggered sequential reactions, G-quadruplex (G4) and DNA (hairpins) modified Ni-Fe layered double oxides (LDOs) could be obtained simultaneously. Later, a three-dimensional G4/LDO frame networks, as a novel DNAzyme, with enhanced peroxidase-like catalytic activity was assembled through electrostatic interaction. This DNAzyme catalyzed 3,3',5,5'-tetramethylbenzidine oxidation for the colorimetric detection of Kana. The enhancement principle was discussed and the charge transfer process during the catalytic reaction was investigated. Under the optimal experiment conditions, the proposed method exhibited high sensitivity, where the linear range is from 10 fM to 10 nM (r² = 0.992), and the limit of detection is 3 fM (S/N = 3). The practicability of this assay was demonstrated by successfully application of residual Kana detection in genuine milk and urine samples.

Simultaneous Quantification of Ampicillin and Kanamycin in Water Samples Based on Lateral Flow Aptasensor Strip with an Internal Line

In this work, a simple and rapid method based on the lateral flow assay (LFA) has been developed for the detection of dual antibiotics. To achieve the quantitative assay and to reduce the non-specific adsorption, an internal system has been developed. A non-specific DNA was exploited as an internal standard and could be recognized by the DNA marker that was coated at the internal line. Two different kinds of aptamers were applied to recognize ampicillin (AMP) and kanamycin (KAM), and the distance between the detection line and conjugate pad was then optimized. Under the optimum conditions, the quantitative assays of AMP (R² = 0.984) and KAM (R² = 0.990) were achieved with dynamic ranges of 0.50 to 500.0 ng/L, and of 0.50 to 1000.0 ng/L, respectively. The LOQs of AMP and KAM were 0.06 ng/L and 0.015 ng/L, respectively. Finally, the proposed method has been successfully applied to analyze aquaculture water, tap water, and lake water, and hospital wastewater, indicating the established method could be used to monitor the environment.

Advances in aptamer screening and aptasensors' detection of heavy metal ions

Heavy metal pollution has become more and more serious with industrial development and resource exploitation. Because heavy metal ions are difficult to be biodegraded, they accumulate in the human body and cause serious threat to human health. However, the conventional methods to detect heavy metal ions are more strictly to the requirements by detection equipment, sample pretreatment, experimental environment, etc. Aptasensor has the advantages of strong specificity, high sensitivity and simple preparation to detect small molecules, which provides a new direction platform in the detection of heavy metal ions. This paper reviews the selection of aptamers as target for heavy metal ions since the 21th century and aptasensors application for detection of heavy metal ions that were reported in the past five years. Firstly, the selection methods for aptamers with high specificity and high affinity are introduced. Construction methods and research progress on sensor based aptamers as recognition element are also introduced systematically. Finally, the challenges and future opportunities of aptasensors in detecting heavy metal ions are discussed.

Electrochemical Biosensors in Food Safety: Challenges and Perspectives

Safety and quality are key issues for the food industry. Consequently, there is growing demand to preserve the food chain and products against substances toxic, harmful to human health, such as contaminants, allergens, toxins, or pathogens. For this reason, it is mandatory to develop highly sensitive, reliable, rapid, and cost-effective sensing systems/devices, such as electrochemical sensors/biosensors. Generally, conventional techniques are limited by long analyses, expensive and complex procedures, and skilled personnel. Therefore, developing performant electrochemical biosensors can significantly support the screening of food chains and products. Here, we report some of the recent developments in this area and analyze the contributions produced by electrochemical biosensors in food screening and their challenges.

Contribution of Nanomaterials to the Development of Electrochemical Aptasensors for the Detection of Antimicrobial Residues in Food Products

The detection of antimicrobial residues in food products of animal origin is of utmost importance. Indeed antimicrobial residues could be present in animal derived food products because of animal treatments for curative purposes or from illegal use. The usual screening methods to detect antimicrobial residues in food are microbiological, immunological or physico-chemical methods. The development of biosensors to propose sensitive, cheap and quick alternatives to classical methods is constantly increasing. Aptasensors are one of the major trends proposed in the literature, in parallel with the development of immunosensors based on antibodies. The characteristics of electrochemical sensors (i.e., low cost, miniaturization, and portable instrumentation) make them very good candidates to develop screening methods for antimicrobial residues in food products. This review will focus on the recent advances in the development of electrochemical aptasensors for the detection of antimicrobial residues in food products. The contribution of nanomaterials to improve the performance characteristics of electrochemical aptasensors (e.g., Sensitivity, easiness, stability) in the last ten years, as well as signal amplification techniques will be highlighted.

Recent advances in aptamer-based sensors for aminoglycoside antibiotics detection and their applications

Aminoglycoside antibiotics (AAs) have been extensively applied in medical field and animal husbandry owing to desirable broad-spectrum antibacterial activity. Excessive AAs residues in the environment can be accumulated in human body through food chain and cause detrimental effect on human health. The establishment of highly specific, simple and sensitive detection methods for monitoring AAs residues is highly in demand. Aptasensor using aptamer as the biological recognition element is the efficient and promising sensing method for detection of AAs. In this review, we have made a summary of specific aptamers sequences against AAs. Subsequently, we provide a systematical and comprehensive overview of modern techniques in aptasensors for detection of AAs according to optical aptasensors as well as electrochemical aptasensors and further summarize their advantages and disadvantages to compare their applications. In addition, we present an overview of practical applications of aptasensors in sample detection of AAs. Moreover, the current challenges and future trends in this field are also included to reveal a promising perspective for developing novel aptasensors for AAs.

Recent development of antibiotic detection in food and environment: the combination of sensors and nanomaterials

In recent years, the abuse of antibiotics has led to the pollution of soil and water environment, not only poultry husbandry and food manufacturing will be influenced to different degree, but also the human body will produce antibody. The detection of antibiotic content in production and life is imperative. In this review, we provide comprehensive information about chemical sensors and biosensors for antibiotic detection. We classify the currently reported antibiotic detection technologies into chromatography, mass spectrometry, capillary electrophoresis, optical detection, and electrochemistry, introduce some representative examples for each technology, and conclude the advantages and limitations. In particular, the optical and electrochemical methods based on nanomaterials are discussed and evaluated in detail. In addition, the latest research in the detection of antibiotics by photosensitive materials is discussed. Finally, we summarize the pros and cons of various antibiotic detection methods and present a discussion and outlook on the expansion of cross-scientific areas. The synthesis and application of optoelectronic nanomaterials and aptamer screening are discussed and prospected, and the future trends and potential impact of biosensors in antibiotic detection are outlined.Graphical abstract.

Application of Multiplexed Aptasensors in Food Contaminants Detection

The existence of contaminants in food poses a serious threat to human health. In recent years, aptamer sensors (aptasensors) have been developed rapidly for the detection of food contaminants because of their high specificity, design flexibility, and high efficiency. However, the development of high-throughput, highly sensitive, on-site, and cost-effective methods for simultaneous detection of food contaminants is still restricted due to multiple signal overlap or mutual interference and cross-reaction between different analytes with similar molecular structures. To overcome these problems, this Review summarizes some effective strategies from the articles published in recent years about multiplexed aptasensors for the simultaneous detection of food contaminants. This work focuses on the application of multiplexed aptasensors to simultaneously detect antibiotics, pathogens, and mycotoxins in food. These aptasensors mainly contain fluorescent aptasensors, electrochemical aptasensors, surface-enhanced Raman scattering-based aptasensors, microfluidic chip aptasensors, and paper-based multiplexed aptasensors. In addition, this Review also covers the application of nucleic acid cycle amplification and nanomaterial amplification strategies to improve the detection sensitivity. Finally, the limitations and challenges in the design of multiplexed aptasensor are also taken into account.

An impedimetric aptasensor for ultrasensitive detection of Penicillin G based on the use of reduced graphene oxide and gold nanoparticles

The authors describe an impedimetric aptasensor for Penicillin G (PEN) which is an important antibiotic. The method is based on the use of a pencil graphite electrode (PGE) modified with reduced graphene oxide (RGO) and gold nanoparticles (GNPs) for ultrasensitive detection of PEN. The morphology of a bare PGE, RGO/PGE, and GNP/RGO/PGE, and the functional groups on graphene oxide (GO) and RGO were studied using scanning electron microscopy and Fourier transform infrared spectroscopy. Electrochemical impedance spectroscopy was used for detection of PEN by measuring the charge transfer resistance (R_ct). Also, cyclic voltammetry was recorded at potential range of 0.30 to +0.70 V for PGE treatment. This aptamer-based assay has a wide linear range that extends from 1.0 fM to 10 μM, and a limit of detection as low as 0.8 fM. The method was applied to the determination of PEN in spiked milk from cow, sheep, goat and water buffalo. Recoveries ranged from 92% to 104%. The assay is fast, ultrasensitive, high reproducible, and selective over antibiotics such as streptomycin, tetracycline, and sulfadiazine. Graphical abstract Schematic presentation of an impedimetric aptasensor for Penicillin G antibiotic using a pencil graphite electrode (PGE) modified with reduced graphene oxide (RGO) and gold nanoparticles (GNPs). This aptamer based assay has limit of detection as low as 0.8 fM.