Chrysanthemi Flos ‘Hangbaiju’ (HBJ) is a common Chinese medicinal material with the same origin as the medicinal and edible cognate plant in China, whose quality is seriously affected by the place of ...origin. In this study, four stable isotope ratios (δ15N, δ2H, δ13C, and δ18O) and 44 elements were detected and analyzed in 191 HBJ flower samples from six locations in China to trace the origin of HBJ. An ANOVA analysis of δ15N, δ2H, δ13C, and δ18O values, as well as milti-elements, showed that there were significant differences among the six places of origin. Partial least squares discriminant analysis (PLSDA) and one-class partial least squares discriminant analysis (OPLS-DA) models were established to trace the origin of HBJ from these six locations. The results showed that the classification effect of the PLSDA model is poor; however, the established OPLS-DA model can distinguish between products of national geographic origin (Tongxiang City, Zhejiang Province, China) and samples from other origins, among which Ni, Mo, δ13C, Cu, and Ce elements (VIP > 1) contribute the most to this classification. Therefore, this study provides a new method for tracing the origins of HBJ, which is of great significance for the protection of origin labeling of products.
The production season is one of the judgment standards of the green tea quality and spring tea is generally considered of higher quality. Moreover, early spring tea is usually more precious and sells ...for a higher price. Therefore, a multifaceted strategy that integrates lipidomics and metabolomics, based on UPLC-Triple-TOF/MS coupled with chemometrics, was developed to discriminate early spring green tea (ET) and late spring green tea (LT). Twenty-six lipids and forty-five metabolites were identified as characteristic components. As for characteristic lipids, most of glycerophospholipids and acylglycerolipids have higher contents in ET. By contrast, glycoglycerolipids, sphingolipids and hydroxypheophytin a were shown higher levels in LT samples. Most of the differential metabolites identified were more abundant in ET samples. LT samples have much higher catechin, procyanidin B2, and 3',8-dimethoxyapigenin 7-glucoside contents. Based on the integration of differential lipids and metabolites, the reconstructed orthogonal partial least squares discriminant analysis (OPLS-DA) model displayed 100% correct classification rates for harvest time discrimination of green tea samples. These results demonstrated that the integration of lipidomics and metabolomics approaches is a promising method for the discrimination of tea quality.
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•Low cost and environmentally friendly S, N-CQDs were synthesized to detect TCs.•TCs were detected with high specificity and sensitively through IFE mechanism.•This method has been ...successfully applied to determine the content of TCs in food.
In recent years, antibiotic residues in food have been of great concern to regulators and consumers. In this study, a novel fluorescent sensor based on S, N-doped carbon quantum dots (S, N-CQDs) was established for rapid detection of tetracycline antibiotics (TCs). Through the internal filter effect (IFE), QDs fluorescence can be effectively quenched by TCs, endowing it an “off” condition. Under the optimal conditions, the TC concentration in the range of 1.88–60 μmol/L had a good linear relationship with the change of QDs fluorescence intensity, and the limit of detection (LOD) was calculated as 0.56 μmol/L (S/N = 3). Furthermore, the proposed “Turn-off” sensor could be employed to quickly and accurately quantify TCs residues even in milk, honey and tap water. The recovery rate was as high as between 93.61% and 102.31%. The established sensor has great application value in the fields of food safety and drug analysis, and provides broad prospects for the future food industry.
Heavy metal pollution has gradually become one of the most serious problems in global environmental pollution and can invade the environment, food, and medicine, eventually causing irreversible ...damage to the human body. Herein, we construct a multichannel visual fluorescence array sensor based on N-doped carbon dots (NCDs) and gold nanocluster (AuNCs). The sensor comprehensively considered the aggregation-induced enhanced fluorescence (AIE) effect of AuNCs, the electron transfer (ET) effect of NCDs, and the fluorescence resonance energy transfer (FRET) effect of AuNCs@NCDs. It was further combined with PLSDA and PLSR to realize rapid and accurate detection of multiple metal ions in tap water, traditional Chinese medicine (TCM), and soil. The LODs of Cd2+, Pb2+, and Hg2+ were 0.15 μmol/L, 0.20 μmol/L and 0.09 μmol/L, respectively. Simultaneously, we proposed an adjustable fluorescence spectral logic device to meet the different determination requirements towards heavy metals. The analysis result of metal ions can be directly achieved by the four output types, NOT (0, 0, 0), Cd2+ (1, 1, 0), Pb2+ (1, 0, 0) and Hg2+ (0, 0, 1). More interestingly, Cd2+ and Pb2+ can be removed by simple centrifugation or sedimentation, which can be observed through the Tyndall effect. Accordingly, we not only constructed the sensing method of multiple metal ions but also proposed a new strategy for future research on the migration of heavy metal ions from complex environments to TCM.
•Develop a three-channel array sensing for the detection of Cd2+, Pb2+, and Hg2+.•Successful applied to visual detection of various heavy metals in complex samples.•A logic device was designed to quickly discriminate between different metal ions.•Cd2+ and Pb2+ can produce Tyndall effect with AuNCs and be removed by centrifugation.
•A sensitized ratio fluorescence probe based on CQDs and CdTe QDs was constructed.•The composite probe owned a tenfold increase in sensitivity to TCs than single QDs.•The composite probe could ...achieve visual detection of TCs.•Both single TCs and mixed multiple TCs could be recognized in actual samples.
A ratiometric fluorescent probe based on N/S doped carbon dots (N/S-CQDs) and mercaptoacetic acid capped CdTe quantum dots (TGA-CdTe QDs) with sensitized and self-calibration functions was constructed to sensitively detect multiple tetracycline antibiotics (TCs). N/S-CQDs could attach stably to TGA-CdTe QDs and form a new composite ratiometric fluorescent probe that had a more than tenfold increase in sensitivity to TCs compared with each single QD. The probe could detect four common TCs as the color of the probe changed from bright red to dark red, and the limit of detection (LOD) was 1.47 × 10−2–1.78 × 10−2 mg/L. Practical applications of the probe in food and urine were also verified with recovery rates of 95.21%-104.97%. Due to the abundant spectral fingerprints provided by both QDs, this novel probe could accurately recognize not only different single TCs but also mixed TC samples even in actual samples combined with chemometrics.
•MS-based untargeted metabolomics was firstly proposed to identify origins of Chinese wines.•There was strong correlation between geographical origins and metabolic profiles of wines.•The ...differential metabolites were screened as markers by OPLS-DA with pairwise modeling.•Tentative identification of differential metabolites was conducted based on MS and MS2 data.•Reliable OPLS-DA models based on markers were constructed for predicting origins of wines.
Identifying geographical origins of red wines made in specific regions is of significance since the false claim of geographical origins has been frequently exposed in China's wine industry. In this work, an untargeted metabolomic approach based on UPLC-QTOF-MS was established to discriminate geographical origins of Chinese red wines. The principal component analysis (PCA) showed significant differences between wine samples from three famous geographical origins in China. The metabolites contributing to the differentiation were screened by orthogonal partial least squares-discriminant analysis (OPLS-DA) with pairwise modeling. 40 and 46 differential metabolites in positive and negative ionization modes were putatively identified as chemical markers. Furthermore, heatmap visualization and OPLS-DA models were constructed based on these identified markers and external verification wine samples from different regions were successfully discriminated, with recognition rate up to 96.7%. This study indicated that UPLC-QTOF-MS-based untargeted metabolomics has great potential for the geographical origin traceability of Chinese red wines.
In this work, we constructed a machine learning-assisted dual-channel visual sensor array for identifying the origin of Lilium bulbs (BH). Nanogold clusters (AuNCs) and quantum dots (QDs) were ...selected and combined into sensor arrays. The amino acids existed in lilium bulbs could induce aggregation-induced fluorescence enhancement effect (AIEE) of AuNCs through hydrogen bonding. The hydrogen protons released from the amino acids and phenolic acids could interact with the COO- group of QDs, resulting in aggregation-caused quenching (ACQ) of QDs. Due to the different contents of amino acids and phenolic acids in BH from different origins, the sensor array can produce distinct and different fluorescent colors, such as red, blue, green and purple. In conjunction with pattern recognition by the RF model, the sensor array clearly identifies the origin of BH with 94.4% prediction accuracy. The visual sensor array constructed in this work exhibited the advantages of simplicity, speed, accuracy and portability, showing potential application prospects in identifying the origin of food and traditional Chinese medicine.
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•A novel visual sensor array method was constructed for tracing BH origins.•The amino acids in BH could induce AIEE effect of AuNCs through hydrogen bonding.•The protonation and ET effect induced the ACQ of NAC-QDs.•The accuracy of BH origin identification based on dual-channel visual data was 94.4%.
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•A novel 3D-fluorescence sensing based on HN-chitosan polymer probe was proposed for the first time.•The proposed sensing strategy was used to identify and quantify of potential ...adulteration in saffron.•PLS-DA and PCA-LDA models can achieve 100% accuracy for identification of saffron and adulteration saffron.•PLSR were constructed to quantitatively predict adulteration levels in saffron mixture.•The proposed strategy has great potentials in real-life authenticity detection.
Saffron is a candidate for various kinds of fraud to make huge profits. The present study proposed an efficient three-dimensional (3D) fluorescence sensing strategy based on hydrophilic hydrazine-naphthalimide functionalized chitosan (HN-chitosan) polymer probe for rapid identification and quantification of potential adulteration in saffron. The amino functional group in the HN-chitosan probe reacted specifically with the Oxygen-containing group of active ingredients in saffron, amplifying the signal difference between saffron and the adulterants, which was comprehensively characterized by 3D fluorescence. Four advanced chemometrics methods were applied for the classification of saffron and adulterated saffron, and good performance were obtained in both training and prediction sets. Furthermore, the PLS regression model was applied to the prediction of adulteration level in saffron and showed satisfactory accuracy. This strategy provides a new solution for rapid identification and quantification of potential adulteration in saffron, which contributes to the healthy development of its industry.
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•A method for predicting species, geographical origin and main compounds of Gancao.•The method was based on 7 components resolved from three-dimensional fluorescence.•The fluorescence ...resolved and prediction algorithm were ATLD and random forest.•The accuracy of this geographical origin discriminant model can reach 94.4%.•The accuracy of main compounds prediction model of Gancao could reach 95.6%.
Glycyrrhizae Radix et Rhizoma (Gancao) is a functional food whose quality varies significantly between distinct geographical sources owing to the influence of genetics and the geographical environment. This study employed three-dimensional fluorescence coupled with alternating trilinear decomposition (ATLD) and random forest (RF) algorithms to rapidly predict Gancao species, geographical origins, and primary constituents. Seven fluorescent components were resolved from the three-dimensional fluorescence of the ATLD for subsequent analysis. Results indicated that the RF model distinguished Gancao from various species and origins better than other algorithms, achieving an accuracy of 94.4 % and 88.9 %, respectively. Furthermore, the RF regressor algorithm was used to predict the concentrations of liquiritin and glycyrrhizic acid in Gancao, with 96.4 % and 95.6 % prediction accuracies compared to HPLC, respectively. This approach offers a novel means of objectively evaluating the origin of food and holds substantial promise for food quality assessment.
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•A visual sensor was developed to identify the origins and growth years of LB.•Catechins in LB combined with Au-AgNCs to produce AIE effect.•DD-SIMCA and PLSDA models achieved 100% ...accuracy of the origins and growth years.•This strategy has great potentials for identifying origins of LB and other foods.
In this study, we developed a cost-effective fluorescence visual sensor strategy based on gold and silver nanocluster (Au-AgNCs) for the rapid identification of the origins and growth years of Lilium bulbs (LB). Au-AgNCs combined with catechins in LB produce aggregation-induced emission (AIE). The catechin content in LB of different origins and growth years varied, resulting in different fluorescence color responses of the sensor system. Furthermore, the RGB values of the fluorescent color were extracted, and the discriminant effect of visual visualisation was verified using the data-driven soft independent modelling of class analogy (DD-SIMCA) and partial least squares discriminant analysis (PLSDA) models. The results showed that the accuracy of DD-SIMCA for identifying LB origins and PLSDA for growth year identification was 100%. These results indicated that the established strategy could accurately identify the quality of LB, which has great potential for application in the rapid and visual identification of other foods.
