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Pan Y, Jiang J, Kan X. Diazo-reaction based dual-mode colorimetric-electrochemical sensing of nitrite in pickled food. Analyst 2023; 148:4869-4876. [PMID: 37642153 DOI: 10.1039/d3an01196h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Development of an effective and convenient sensor for sensitive detection of nitrites is of great concern since excessive amounts of nitrites can be harmful to both human health and the environment. In this work, Cu-MOF modified exfoliated graphite paper (EGP) was employed as a signal reporter to enable the visual and electrochemical dual-mode sensing of nitrites. Cu-MOFs were in situ synthesized on EGP, which exhibited an excellent oxidase enzyme-like activity to oxidize 3,3',5,5'-tetramethylbenzidine (TMB) into its oxidation product (oxTMB). The multi-layer structure and the superior electrical conductivity of EGP not only facilitated the loading of the Cu-MOF nanozyme for colorimetric sensing but also enabled its use as an underlying backbone to support electroanalysis. Based on the recognition of nitrite through a highly specific diazo reaction between nitrite and oxTMB, the addition of nitrite caused the colorimetric sensing solution to change color from blue to green, which allowed for the colorimetric sensing of nitrite with a limit of detection (LOD) of 8.5 × 10-6 mol L-1. Meanwhile, the Cu-MOF/EGP electrochemical platform was employed for ratiometric detection of nitrite based on the electrochemical oxidation of nitrite and TMB. Compared with the colorimetric mode, the electrochemical mode possessed higher sensitivity with a LOD of 5.4 × 10-7 mol L-1, indicating the high sensitivity and accuracy of the proposed dual-mode sensing strategy. Furthermore, the determination of nitrite in different pickled food samples is demonstrated.
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Affiliation(s)
- Yixin Pan
- College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, P. R. China
- The Key Laboratory of Functional Molecular Solids, Ministry of Education; Anhui Laboratory of Molecule-Based Materials, Anhui Key Laboratory of Chemo-Biosensing, China.
| | - Jing Jiang
- College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, P. R. China
- The Key Laboratory of Functional Molecular Solids, Ministry of Education; Anhui Laboratory of Molecule-Based Materials, Anhui Key Laboratory of Chemo-Biosensing, China.
| | - Xianwen Kan
- College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, P. R. China
- The Key Laboratory of Functional Molecular Solids, Ministry of Education; Anhui Laboratory of Molecule-Based Materials, Anhui Key Laboratory of Chemo-Biosensing, China.
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Moreno-Castilla C, Naranjo Á, Victoria López-Ramón M, Siles E, López-Peñalver JJ, de Almodóvar JMR. Influence of the hydrodynamic size and ζ potential of manganese ferrite nanozymes as peroxidase-mimicking catalysts at pH 4 in different buffers. J Catal 2022. [DOI: 10.1016/j.jcat.2022.09.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Li R, He X, Javed R, Cai J, Cao H, Liu X, Chen Q, Ye D, Zhao H. Switching on-off-on colorimetric sensor based on Fe-N/S-C single-atom nanozyme for ultrasensitive and multimodal detection of Hg 2. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155428. [PMID: 35469883 DOI: 10.1016/j.scitotenv.2022.155428] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/28/2022] [Accepted: 04/17/2022] [Indexed: 05/15/2023]
Abstract
Single-atom nanozymes (SAzymes) as a new class of efficient nanozymes have attracted extensive research interest due to their high catalytic activity and specificity. However, it is challenging to develop a novel nanoenzyme with high activity, good stability and reproducibility. In this paper, the nitrogen and sulfur coordinated Fe-N/S-C SAzymes were synthesized using peanuts shells as carbon, nitrogen and sulfur source. It shows high oxidase-like activities due to the doping of S induced geometric and electronic effects, which is further confirmed by density functional theory calculations. The prepared Fe-N/S-C SAzymes with the remarkable oxidase-mimicking activity could oxidize TMB to blue oxTMB, but the GSH can inhibit the oxidation of TMB resulting in blue fading. However, when Hg2+ is added into above system, Hg2+-SH complexes are generated attributed to a high affinity between GSH and Hg2+, ultimately leading to blue recovery. Based on this phenomenon, we constructed a novel "on-off-on" colorimetric sensor for the simultaneous detection of GSH (off) and Hg2+ (on), and the signal is acquired by various modes such as naked eye, UV-Vis spectrometer and smartphone. The colorimetric detection mode based on a smartphone showed a good linear response from 10 to 80 μM for GSH with a detection limit of 3.92 μM, and for Hg2+ with a linear range of 1 nM-10 μM and LOD of 0.17 nM, which is more suitable for routine laboratory applications. More importantly, the proposed colorimetric sensor has been successfully applied to the detection of GSH and Hg2+ in real samples with good analytical performance. This work not only provides a simple and cost-effective method to detect GSH and Hg2+ but also makes a certain contribution to environmental protection.
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Affiliation(s)
- Rui Li
- College of Food Science and Engineering, Key Laboratory of Tropical and Vegetables Quality and Safety for State Market Regulation, Hainan University, Haikou 570228, China
| | - Xiaoting He
- College of Food Science and Engineering, Key Laboratory of Tropical and Vegetables Quality and Safety for State Market Regulation, Hainan University, Haikou 570228, China
| | - Rida Javed
- Institute for Sustainable Energy, College of Sciences, Shanghai University, Shanghai 200444, PR China
| | - Jian Cai
- Institute for Sustainable Energy, College of Sciences, Shanghai University, Shanghai 200444, PR China
| | - Hongmei Cao
- College of Food Science and Engineering, Key Laboratory of Tropical and Vegetables Quality and Safety for State Market Regulation, Hainan University, Haikou 570228, China; Key Laboratory of Food Nutrition and Functional Food of Hainan Province, 58 Renmin Avenue, Haikou 570228, China.
| | - Xing Liu
- College of Food Science and Engineering, Key Laboratory of Tropical and Vegetables Quality and Safety for State Market Regulation, Hainan University, Haikou 570228, China
| | - Qi Chen
- College of Food Science and Engineering, Key Laboratory of Tropical and Vegetables Quality and Safety for State Market Regulation, Hainan University, Haikou 570228, China
| | - Daixin Ye
- Institute for Sustainable Energy, College of Sciences, Shanghai University, Shanghai 200444, PR China.
| | - Hongbin Zhao
- Institute for Sustainable Energy, College of Sciences, Shanghai University, Shanghai 200444, PR China.
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Boosting the oxidase-like activity of platinum nanozyme in MBTH-TOOS chromogenic system for detection of trypsin and its inhibitor. Talanta 2021; 234:122647. [PMID: 34364456 DOI: 10.1016/j.talanta.2021.122647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/23/2022]
Abstract
Nanozymes, as a new type of artificial enzyme, have recently become a research hotspot in the field of catalysis and biomedicine. However, the application of nanozyme is limited by catalytic activity changes of different substrates and low specificity. This work shows that citrate-capped platinum nanoparticles (Cit-PtNPs) exhibit stronger oxidase-like activity than other platinum nanozymes at different pH when 3-methyl-2-benzothiazolinonehydrazone hydrochloride (MBTH) and n-ethyl-n- (2-hydroxy-3-sulfopropyl)-m-toluidine sodium salt (TOOS) were used as chromogenic substrates. This phenomenon has important reference value for different nanozymes to choose chromogenic substrates in catalysis. In MBTH-TOOS chromogenic system, MBTH (-NH) radical is first produced during the reaction through catalytic oxidation of Cit-PtNPs, which reacts with TOOS to produce a colorless compound. The blue-purple quinoid dye was produced through the dismutation of the colorless compound. The catalytic mechanism of the oxidase-like activity of Cit-PtNPs is that two-electron reduction process and four-electron reduction process are simultaneously carried out in the catalytic process. Furthermore, to solve the problem of low specificity of metal nanozymes, protamine is designed as aggregation promoter of Cit-PtNPs and the specifichydrolysis substrate of trypsin. In this work, it can achieve one-step detection of trypsin by the boosting oxidase activity of Cit-PtNPs at pH8. The catalytic activity of Cit-PtNPs is proportional to the concentration of trypsin. The linear range for trypsin is 1.0-70.0 ngmL-1 and the limit of detection is measured to be 0.6 ngmL-1. This novel method has also been successfully applied to the detection of inhibitors and trypsin in urine samples.
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