1
|
Wang X, Zu X, Wang T, Zhao Y, Liang Y, Wang X, Chai Q, Zhang Y, Chen H, Wang H. N, S-Doped Carbon Dots Prepared by Peanut Protein Isolates and Cysteamine as Highly Sensitive Fluorescent Sensors for Fe 2+, Fe 3+ and Lactoferrin. Polymers (Basel) 2022; 15:polym15010216. [PMID: 36616565 PMCID: PMC9823515 DOI: 10.3390/polym15010216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/21/2022] [Accepted: 12/26/2022] [Indexed: 01/03/2023] Open
Abstract
Lactoferrin (LF) is an iron-binding glycoprotein with various biological activities that has been extensively used in food and medical applications. Several methods for detecting LF have been reported, but they still face challenges in terms of sensitivity and simplicity of detection. To achieve an accurate and efficient detection of LF, we developed a method for the determination of LF in lactoferrin supplements using carbon dots (CDs) fluorescent probes. The N, S-doped PPI carbon dots (N, S-PPI-CDs) were prepared using a protein (peanut protein isolate) and cysteamine as precursors. The prepared N, S-PPI-CDs exhibited intense blue fluorescence and good biocompatibility, while the fluorescence intensity of the N, S-PPI-CDs showed a good linear relationship with Fe2+/Fe3+ concentration (0-2 μM). The N, S-PPI-CDs exhibited a high potential ability to rapidly detect Fe2+/Fe3+ within 30 s, with a limit of detection (LoD) of 0.21 μM/0.17 μM. Due to the reversible binding of LF to Fe, the N, S-PPI-CDs showed a high sensitivity and selectivity for LF, with a limit of detection (LoD) of 1.92 μg/mL. In addition, LF was quantified in real sample LF supplements and showed a fluctuation in recovery of less than 2.48%, further demonstrating the effectiveness of the fluorescent N, S-PPI-CDs sensor.
Collapse
Affiliation(s)
- Xinxin Wang
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Xinyu Zu
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Ting Wang
- College of Biotechnology, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Yanan Zhao
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Yan Liang
- State Key Laboratory of Biobased Material and Green Papermaking, School of Food Sciences and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Correspondence: (Y.L.); (H.W.)
| | - Xiaochen Wang
- Shandong Center for Food and Drug Evaluation & Inspection, Jinan 250014, China
| | - Qian Chai
- Shandong Center for Food and Drug Evaluation & Inspection, Jinan 250014, China
| | - Yunjuan Zhang
- Shandong Center for Food and Drug Evaluation & Inspection, Jinan 250014, China
| | - Hongzhong Chen
- Shandong Center for Food and Drug Evaluation & Inspection, Jinan 250014, China
| | - Hua Wang
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China
- Correspondence: (Y.L.); (H.W.)
| |
Collapse
|
2
|
Development of an optical immunoassay based on peroxidase-mimicking Prussian blue nanoparticles and a label-free electrochemical immunosensor for accurate and sensitive quantification of milk species adulteration. Mikrochim Acta 2022; 189:209. [PMID: 35501410 DOI: 10.1007/s00604-022-05302-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 03/30/2022] [Indexed: 10/18/2022]
Abstract
In contrast to reported enzyme-based immunoassays, an enzyme-free immunoassay (optical and electrochemical) is presented here for the first time that can be used as point-of-need detection bioplatforms of bovine IgG as goat milk adulterant. In the first format, Prussian blue nanoparticles (PBNPs) were used as antibody catalytic labels in a competitive colorimetric microplate immunoassay. Absorbance measurement was performed photometrically at 450 nm. After in-depth optimization, excellent sensitivity was achieved (0.01% cow/goat volume ratio), which is 100 times lower than the limit allowed by the European legislation (EL) (1% v/v), thanks to the high catalytic activity of PBNPs compared with natural peroxidase. Moreover, the antibody-PBNPs bioconjugates showed excellent stability over 4 weeks (> 94% of the initial response) confirming the successful anchoring of the antibodies to the surface of the PBNPs. On the other hand, a label-free voltammetric immunoassay for the detection of bovine IgG was developed. The sensing principle was based on the hindrance of charge transfer between ferri-ferrocyanide redox couple and the screen-printed gold electrodes modified with bovine IgG antibody. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the step-by-step modification of the electrode surface. Under optimal conditions, this single-step electrochemical analysis achieved a high sensitivity of 0.1% (cow/goat) when monitoring the ferrocyanide oxidation at + 0.092 V (vs. Ag/AgCl) using differential pulse voltammetry (DPV). The selectivity of the developed immunoassays was evaluated for different species of milk of similar composition, and both immunoassays exhibited a selective response only to bovine IgG. Unlike conventional immunoassays, the developed enzyme-free immunoassays have many attractive features for the detection of milk adulteration, whether they are used in quality control laboratories for routine milk analysis (optical immunoassay) or at on-site checkpoints (electrochemical immunoassay) using wireless electrochemical detectors. The sensors provide high sensitivity (≤ 0.1%), excellent precision (RSD < 6%), low cost (no enzyme is required) and ease of operation, including handling of milk samples.
Collapse
|
3
|
Ostertag F, Sommer D, Berensmeier S, Hinrichs J. Development and validation of an enzyme-linked immunosorbent assay for the determination of bovine lactoferrin in various milk products. Int Dairy J 2022. [DOI: 10.1016/j.idairyj.2021.105246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
4
|
Wang X, Zhao Y, Wang T, Liang Y, Zhao X, Tang K, Guan Y, Wang H. Carboxyl-Rich Carbon Dots as Highly Selective and Sensitive Fluorescent Sensor for Detection of Fe 3+ in Water and Lactoferrin. Polymers (Basel) 2021; 13:4317. [PMID: 34960868 PMCID: PMC8706276 DOI: 10.3390/polym13244317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022] Open
Abstract
As lactoferrin (LF) plays an essential role in physiological processes, the detection of LF has attracted increasing attention in the field of disease diagnosis. However, most current methods require expensive equipment, laborious pretreatment, and long processing time. In this work, carboxyl-rich carbon dots (COOH-CDs) were facilely prepared through a one-step, low-cost hydrothermal process with tartaric acid as the precursor. The COOH-CDs had abundant carboxyl on the surface and showed strong blue emission. Moreover, COOH-CDs were used as a fluorescent sensor toward Fe3+ and showed high selectivity for Fe3+ with the limit of detection (LoD) of 3.18 nM. Density functional theory (DFT) calculations were performed to reveal the mechanism of excellent performance for Fe3+ detection. Meanwhile, COOH-CDs showed no obvious effect on lactobacillus plantarum growth, which means that COOH-CDs have good biocompatibility. Due to the nontoxicity and excellent detection performance for Fe3+, COOH-CDs were employed as a fluorescent sensor toward LF and showed satisfying performance with an LoD of 0.776 µg/mL, which was better than those of the other methods.
Collapse
Affiliation(s)
- Xinxin Wang
- College of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.W.); (Y.Z.); (X.Z.); (Y.G.)
| | - Yanan Zhao
- College of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.W.); (Y.Z.); (X.Z.); (Y.G.)
| | - Ting Wang
- College of Biotechnology, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (T.W.); (K.T.)
| | - Yan Liang
- College of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.W.); (Y.Z.); (X.Z.); (Y.G.)
| | - Xiangzhong Zhao
- College of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.W.); (Y.Z.); (X.Z.); (Y.G.)
| | - Ke Tang
- College of Biotechnology, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (T.W.); (K.T.)
| | - Yutong Guan
- College of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (X.W.); (Y.Z.); (X.Z.); (Y.G.)
| | - Hua Wang
- School of Materials Science and Engineering, Shandong University, Jinan 250061, China
| |
Collapse
|
5
|
High-efficiency selection of aptamers for bovine lactoferrin by capillary electrophoresis and its aptasensor application in milk powder. Talanta 2019; 205:120088. [PMID: 31450439 DOI: 10.1016/j.talanta.2019.06.088] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/14/2019] [Accepted: 06/26/2019] [Indexed: 02/07/2023]
Abstract
Capillary electrophoresis-based systematic evolution of ligands by exponential enrichment (CE-SELEX) is a high-efficient technique for aptamers selection, and has been evolved into many modes. In this study, we obtained the aptamer against bovine lactoferrin (BLF) with high affinity (dissociation constant, Kd = 20.74 ± 6.89 nM) and good specificity (>1000 folds) using single step CE-SELEX (ssCE-SELEX) mode. In the selection process, ssCE demonstrated high-efficiency selection with bulk Kd reaching at 0.19 ± 0.04 μM by only two rounds, as compared to capillary zone electrophoresis (CZE) mode with Kd of 0.39 ± 0.03 μM. Next-generation sequencing (NGS) was performed by two methods of high output (Hiseq) and medium output (Miseq) with different sequencing depths, and their same results of high-frequency sequences confirmed the reliability of the obtained sequences. Through affinity analysis, the primer region and single base mutation (SBM) were observed to affect the sequence structure and to result in affinity change. Besides, molecular dynamics (MD) simulation was performed to validate the binding affinity of the candidates with BLF by analyzing binding sites, interaction forces, and binding free energy. Moreover, BLF detection in milk powder matrices was completed successfully with the optimized CE-aptasensor. The signal response was in a good linear relationship (R2 = 0.9930) with 4-128 nM of BLF and the detection limit was 1 nM. The obtained results of BLF in four milk powder samples were in an acceptable agreement with the labeled concentrations. This study presented a completed CE based process including aptamers selection, affinity characterization, and detection application, which also validated the high-efficiency selection of ssCE-SELEX mode.
Collapse
|
6
|
Shao Y, Wang Z. Changes in the nutrients of camels’ milk alter the functional features of the intestine microbiota. Food Funct 2018; 9:6484-6494. [DOI: 10.1039/c8fo00812d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Heat treatment alters the nutritive quality of camels' milk and thus the intestine microbiota, but the effect of heat treatment-induced nutrient loss on the functional features of the intestine microbiota is unknown.
Collapse
Affiliation(s)
- Yuyu Shao
- College of Food Engineering and Nutritional Science
- Shaanxi Normal University
- Xi'an
- China
| | - Zhaoxia Wang
- College of Food Engineering and Nutritional Science
- Shaanxi Normal University
- Xi'an
- China
| |
Collapse
|