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Inspired by the desert beetle, a novel biomimetic chip was developed to detect chloramphenicol (CP). The chip was characterized by a periodic array in which hydrophobic Au nanoparticles (AuNPs) were semi-embedded on hydrophilic polymethyl methacrylate (PMMA) spheres. Among them, the AuNPs exhibited both a localized surface plasmon resonance effect to amplify the reflected signal and a synergistic effect with PMMA spheres to create a significant hydrophilic-hydrophobic interface, which facilitated the enrichment of target CP molecules and improved sensitivity. After optimization, the chip showed direct, ultrasensitive (as low as 0.2 ng/mL), fast (5 min), and selective detection of CP with a wide concentration range extending from 0.2 ng/mL to 1000 ng/mL. During detection, color changes of the chip were observed by naked eyes without any color display equipment. The recovery of CP was between 94.65 % and 108.70 % in chicken and milk samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A novel photonic crystal (PC) for the enrichment and detection of trace chloramphenicol (Cm) was constructed based on the combination of the imprinted crystalline colloidal array (ICCA) and the enrichment effect induced by wettability differences. The enrichment ICCA (E-ICCA) material had a highly ordered opal structure consisted of hydrophilic molecular imprinting polymer (MIP) spheres and the surrounding hydrophobic polydimethylsiloxane (PDMS) matrix, thus showing the desired structural color but also possessing the large hydrophilicity/hydrophobicity (HP) interaction area to enable efficient enrichment of the target Cm molecules from a highly dilute solution to the MIP sphere surface. The sensitive Cm recognition of MIP spheres finally caused the reduced reflection intensity and a red shift of the material due to changes of the periodic structure. Using this sensing platform, the highly sensitive detection of Cm (as low as 1.5×10 -9 M) with high selectivity was achieved without using label techniques and expensive detection instruments. Furthermore, the developed method successfully used to screen Cm in drinking water samples. Therefore, this approach is extensible to the construction of many sensor systems for the sensitive detection of drugs, diseases, and pollutions of food and the environment., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A novel enzyme liked immunosorbent assay (ELISA) was developed for the detection of chloramphenicol (CAP). In this assay, the small molecular hapten (Hap) was directly coated on the surface of microtiter plates and biotin-streptavidin system (BSAS) was employed to improve the sensitivity of immunoassay (BSAS-direct Hap coated ELISA). The surface of microtiter plates was treated with glutaraldehyde (GA) polymer network to introduce aldehyde group, which was used to cross-link with amino group of CAP. Compared with conventional ELISA (the plates were coated with Hap-carrier protein conjugates), the modified plates presented significantly high antibody and antigen (Ab-Ag) affinity and showed excellent stability. And then the biotinylated monoclonal antibody (mAb) and HRP-labeled streptavidin were employed in this assay for amplification of signals. The sensitivity of BSAS-direct Hap coated ELISA was increased by approximately 20-folds and the stability was also improved greatly compared to conventional ELISA. Its 50% inhibition concentration (IC(50)) for CAP was 10.5 ng mL(-1) and the limit of detection (LOD) was 0.2 ng mL(-1) after optimization of reaction conditions. To our knowledge, this was one of the most sensitive immunoassay for CAP yet reported. In sample analysis, the results of CAP detected by this assay were in accordance with which obtained by conventional ELISA and high performance liquid chromatography (HPLC). Therefore, it is an attractive alternative compared to conventional immunoassays in routine supervision for residue detection in food and environment., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

A novel photonic sensor using a self-cross-linked imprinting close-packed opal (CPO) as a recognition element was developed for the detection of chloramphenicol (CAP). The self-cross-linked imprinting CPO film was consisted of monodisperse molecular imprinted – N-hydroxymethylacrylamide particles (MI-HAM particles) with self-assembling and self-crosslinking properties. A dilute dispersion of these particles was self-assembled to formation of the highly ordered CPO structure, and at the same time the neighboring particles reacted to form covalent bond to stabilize the CPO structure at the air/dispersion. Thus the obtained self-cross-linked imprinting CPO was characterized by a highly stable three-dimensional (3D) CPO structure without the interference of bulk hydrogel matrix, in which numerous CAP recognition sites were dispersed through the molecular imprinted process. The inherent high affinity of the recognition sites allowed the self-cross-linked imprinting CPO to recognize CAP with high specificity, and changes of the periodic structure enabled the self-cross-linked imprinting CPO to transfer the recognition events into readable optical signals. Then the self-cross-linked imprinting CPO film was packed into a reaction cell with an optical spectrometer to establish a novel photonic sensor. A linear relationship was found between the diffraction intensity decrease and CAP concentration in the range from 2 ng mL−1 to 512 ng mL−1, whereas there was no obvious optical change for CAP analogues, thus indicating that the sensor had selective and sensitive response to CAP molecules. Furthermore, the sensor was applied successfully to detect CAP in drinking water samples. As a result, the developed sensor might offer a potential alternative in routine supervision for residue due to its convenience, low cost, reusability, and high sensitivity as well as selectivity. [ABSTRACT FROM AUTHOR]