Differential-based biosensor array for fluorescence-chemometric discrimination and the quantification of subtle chloropropanols by cross-reactive serum albumin scaffolding

A comprehensive review of chloropropanol analytical method in the context of food safety

Chloropropanols are among the major food contaminants, and quantifying their content in food is a key food-safety issue. In response to the demand for highly sensitive and selective analysis, the scientific community is committed to continuous innovation and optimization of various analytical techniques. This paper comprehensively reviews the latest developments in chloropropanol analysis technologies and systematically compares and analyzes the working principles, application conditions, advantages, and challenges of these methods. Gas chromatography-mass spectrometry is the preferred choice for chloropropanol analysis in complex sample matrices owing to its high resolution, sensitivity, and accuracy. Electrochemical methods provide strong support for the real-time monitoring of chloropropanols because of their high selectivity and sensitivity towards electrochemically active molecules. Other techniques offer innovative solutions for the rapid and accurate analysis of chloropropanol at different levels. Finally, innovative directions for the development of chloropropanol analysis methods for food safety are highlighted.

Methods, principles, challenges, and perspectives of determining chloropropanols and their esters

Chloropropanols and their esters are a group of food contaminants that have various toxicities to the human body. Research and control to chloropropanols and their esters is important to food safety. Therefore, the sensitive, accurate, precise, and effective determination of chloropropanols and their esters is highly essential to study their concentration, formation, and mitigation. The indirect method, commonly applied in the determination of chloropropanols and their esters, is based on the cleavage of ester bond, extraction, and derivatization. The conventional indirect method will still be the mostly used method in the near future due to its good sensitivity and feasibility, although its parameters need to be chosen and optimized according to sample stuffs and chloropropanol concentrations. Meanwhile, direct method and other quantitative methods should also be developed for special applications, such as studying the profile of chloropropanol esters and rapid screening protocol. The challenges and future perspectives of these methods are discussed in this review. This review can provide a reference on the selection, designation, and modification of methods for determining chloropropanols and their esters.

Factors Affecting the Leaching of Chloropropanols from Pulp Used in the Manufacture of Paper Food Packaging

Paper packaging materials are widely used in food packaging. However, it is difficult to extract trace chloropropanol from food packaging paper, so there is a lack of research on the leaching of chloropropanol from paper materials. Therefore, it is of positive significance to explore the leaching rule of chloropropanol in paper pulp for the safety of paper packaging materials, to reduce the risk of food packaging to food safety and to provide a theoretical basis for the formulation of safety standards for paper packaging materials. In order to study the content of chloropropanol in paper packaging paper more accurately, a response surface methodology was used to study the relationship between the amount of chloropropanol leaching and pulp concentration, leaching temperature and leaching time, as well as the interaction of each factor. The results showed that time, temperature and pulp concentration were the main factors affecting the leaching amount of chloropropanol from paper packaging materials. There were significant (p > 0.05) interactions between the time and pulp concentration, as well as temperature and pulp concentration. The leaching efficiency of chloropropanol was higher at a lower pulp concentration, and the leaching amount of chloropropanol was higher at a lower temperature. The temperature more significantly affected the leaching of chloropropanol in a low-concentration system than in a high-concentration system. Relevant studies have shown that the selection of solvent has an important effect on the extraction rate of target compounds. Therefore, in this experiment, different polar organic solvents (methanol, ethanol, formaldehyde solution) were added into the soaking solution to change the leaching amount of chloropropanol. The results showed that adding a certain amount of formaldehyde solution can obviously increase the leaching amount of chloropropanol in pulp.

Coding recognition of the dose-effect interdependence of small biomolecules encrypted on paired chromatographic-based microassay arrays

The discovery of small biomolecules has suffered from the lack of a comprehensive framework to express the intrinsic correlation between bioactivity and the contribution from small molecules in complex samples with molecular and bioactivity diversity. Here, by mapping a sample’s 2D-HPTLC fingerprint to microplates, paired chromatographic-based microassay arrays are created, which can be used as quasi-chips to characterize multiple attributes of chromatographic components; as the array differential expression of the bioactivity and molecular attributes of irregular chromatographic spots for dose–effect interdependent encoding; and also as the automatic-collimated array mosaics of the multi-attributes of each component itself encrypted by its chromatographic fingerprint. Based on this homologous framework, we propose a correlating recognition strategy for small biomolecules through their self-consistent chromatographic behavior characteristics. In the approach, the small biomolecule recognition in diverse compounds is transformed into a constraint satisfaction problem, which is addressed through examining the dose–effect interdependence of the homologous 2D code pairs by an array matching algorithm, instead of preparing diverse compound monomers of complex test samples for identification item-by-item. Furthermore, considering the dose–effect interdependent 2D code pairs as links and the digital-specific quasimolecular ions as nodes, an extendable self-consistent framework that correlates mammalian cell phenotypic and target-based bioassays with small biomolecules is established. Therefore, the small molecule contributions and the correlations of bioactivities, as well as their pathways, can be comprehensively revealed, so as to improve the reliability and efficiency of screening. This strategy was successfully applied to galangal, and demonstrated the high-throughput digital preliminary screening of small biomolecules in a natural product.

Determination of chloropropanol with an imprinted electrochemical sensor based on multi-walled carbon nanotubes/metal-organic framework composites

In this paper, a composite composed of carboxylated multi-wall carbon nanotubes (cMWCNT) incorporated in a metal–organic framework (MOF-199) has been synthesized using 1,3,5-benzoic acid as a ligand through a simple solvothermal method. The synthesized cMWCNT/MOF-199 composite was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffractometry (XRD). The cMWCNT/MOF-199 hybrids were modified on the surface of glassy carbon electrodes (GCE) to prepare a molecularly imprinted electrochemical sensor (MIECS) for specific recognition of 3-chloro-1,2-propanediol (3-MCPD). The electrodes were characterized by differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Under optimal conditions, the electrochemical sensor exhibited an excellent sensitivity and high selectivity with a good linear response range from 1.0 × 10⁻⁹ to 1.0 × 10⁻⁵ mol L⁻¹ and an estimated detection limit of 4.3 × 10⁻¹⁰ mol L⁻¹. Furthermore, this method has been successfully applied to the detection of 3-MCPD in soy sauce, and the recovery ranged from 96% to 108%, with RSD lower than 5.5% (n = 3), showing great potential for the selective analysis of 3-MCPD in foodstuffs.

In this study, cMWCNT/MOF-199 composites were used as the modified electrodes, and a MIECS having specific recognition of 3-MCPD was prepared by electrochemical polymerization for selective analysis of 3-MCPD in foodstuffs.

Differential colorimetric nanobiosensor array as bioelectronic tongue for discrimination and quantitation of multiple foodborne carcinogens

Foodborne amides, specifically acrylamide, are vitally important for food safety and security, as they are the most common food toxicants and suspected human carcinogens. A facile and novel differential-based colorimetric nanobiosensor array composed of three surface-bioengineered gold nanoparticles (AuNPs) was developed for the rapid detection, differentiation, and quantification of acrylamide and six analogues. Diverse cross-reactive receptors demonstrated differential binding affinities toward target analytes, resulting in distinctive AuNP aggregation behaviors and distinguishable response patterns. The sensor array, integrated with principal component analysis and hierarchical cluster analysis, accurately discriminated foodborne amides based on their amine subgroups, International Agency for Research on Cancer (IARC) carcinogen classifications, and food additive types, even at ultra-low concentrations (500 pM). Additionally, the sensor array successfully differentiated non-targeted analytes by sweetener and food ingredients types with 100% correct classification. Partial least squares regression outcomes exhibited high correlation coefficients (R2 > 0.95). Thus, the sensor array has practical potential for food safety monitoring in the food and beverage industries.

Application of Chemometrics in Biosensing: A Review

The field of biosensing is rapidly developing, and the number of novel sensor architectures and different sensing elements is growing fast. One of the most important features of all biosensors is their very high selectivity stemming from the use of bioreceptor recognition elements. The typical calibration of a biosensor requires simple univariate regression to relate a response value with an analyte concentration. Nevertheless, dealing with complex real-world sample matrices may sometimes lead to undesired interference effects from various components. This is where chemometric tools can do a good job in extracting relevant information, improving selectivity, circumventing a non-linearity in a response. This brief review aims to discuss the motivation for the application of chemometric tools in biosensing and provide some examples of such applications from the recent literature.