摘要：
A novel layered perovskite tantalate phosphor Sr3LaTa3O12:Sm3+ (SLTO:Sm3+) with orange-red emission was obtained for the first time via the solid-phase synthetic method. The phase purity, surface morphology, element distribution and luminescent properties of the SLTO:xSm(3+) (x = 0.01 mol%-0.30 mol%) phosphors were investigated. Under 408 nm excitation, the optimum doped SLTO:0.10Sm(3+) phosphor emits orange-red light at 598 nm with the highest emission peak ((4)G(5/2) -> H-6(7/2)). The critical energy transfer distance is 1.687 nm. The prepared SLTO:0.10Sm(3+) phosphor has excellent thermal stability with temperature quenching temperature (T-0.5 > 500 K) and high activation energy (E-a = 0.25 eV). Through calculation, the chromaticity coordinates of all samples are concentrated in the orange-red area, and the color purity reaches 99%. The fabricated white light-emitting diode (w-LED) has a good correlated color temperature (5132 K), a high R-a (89), and the CIE chromaticity coordinates (0.340, 0.327). Consequently, the superiority of orange-red-emitting tantalate SLTO:Sm3+ phosphors for w-LEDs is demonstrated. (c) 2023 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.
期刊：
Biosensors and Bioelectronics,2023年222:114981 ISSN：0956-5663
通讯作者：
Xie, Lianwu;Shi, SY;Guo, Y
作者机构：
[Shi, SY; Shi, Shuyun; Xie, Lianwu; Peng, Yuqing; Tong, Xia] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Hunan, Peoples R China.;[Shi, Shuyun; Wang, Tongtao; Zhu, Yongfeng; Tong, Chaoying; Tong, Xia; Cai, Guihan] Cent South Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Tong, Xia] Shanxi Med Univ, Shanxi Acad Med Sci, Hosp 3, Shanxi Bethune Hosp, Taiyuan 030032, Shanxi, Peoples R China.;[Guo, Ying; Guo, Y] Cent South Univ, Xiangya Hosp, Dept Clin Pharmacol, Hunan Key Lab Pharmacogenet, Changsha 410078, Hunan, Peoples R China.
通讯机构：
[Shi, SY ; Xie, LW; Guo, Y ] C;Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Hunan, Peoples R China.;Cent South Univ, Xiangya Hosp, Dept Clin Pharmacol, Hunan Key Lab Pharmacogenet, Changsha 410078, Hunan, Peoples R China.
关键词：
Background-free analysis;Organophosphorus pesticide;Ratiometric fluorescent system;Threaded 3D microfluidic paper device;Visual detection
摘要：
With the increasing concerns of food safety and environmental protection, it is desirable to develop reliable, effective, and portable sensors for detection of organophosphorus pesticides (OPs). Here, a cascade reaction system integrated with threaded 3D microfluidic paper analytical device (3D μPAD) was firstly developed for background-free and visual detection of OPs in agricultural samples. Butyrylcholinesterase (BChE) hydrolyzed acetylcholine into thiocholine (TCh), which reduced MnO(2) nanosheets into Mn(2+). With addition of OPs, BChE activity was irreversibly inhibited, and the generation of TCh and the reduction of MnO(2) nanosheets were prevented. Then the remaining MnO(2) nanosheets oxidized o-phenylenediamine into 2,3-diaminophenazine with yellow-emission fluorescence, which quenched the fluorescence intensity of red-emission carbon dots (RCDs) via inner-filter effect. Based on above mechanism, a ratiometric fluorescent system was established for OPs detection. Threaded 3D μPAD consisted of 4 layers, which allowed to load and/or add reagents to trigger the cascade reaction system for OPs detection. The fluorescent images presented distinguishable color variations from red to yellow with dichlorvos concentrations ranging from 2.5 to 120μgL(-1), and the limit of detection was 1.0μgL(-1). In the practical samples testing, threaded 3D μPAD can eliminate background influence on fluorescent signal for OPs detection. Threaded 3D μPAD integrated with ratiometric sensing platform has merits of accuracy response, facile operation, and background-free detection, which supplies a new alternative approach for on-site pesticide detection.
摘要：
Novel red-emitting phosphors, Sr3LaTa3O12:Eu3+ (SLTO:Eu3+), have been successfully synthesized for use in white light-emitting diodes (w-LEDs) and latent fingerprint (LFP) visualization applications. The crystalline structure, bandgap, and photoluminescence (PL) of the SLTO:Eu3+ phosphors were thoroughly investigated. Under 395 nm excitation, SLTO:Eu3+ phosphors emitted orange-red light at the wavelength of 616 nm due to the D-5(0)-F-7(2) transition of Eu3+ ions. The optimal doping concentration of the phosphor is x = 0.30 and the neighbor ions interaction is the most critical factor in the concentration quenching mechanism of the SLTO:Eu3+ phosphor. Furthermore, the SLTO:0.30Eu(3+) phosphor exhibit higher thermal stability compared to the conventional red phosphor (Sr2Si5N8:Eu2+). The packaged w-LED showed a correlated color temperature (6887 K), excellent color rendering index (95), and Commission International de l'Eclairage (CIE) coordinates of (0.305, 0.334). The SLTO:0.30Eu(3+) phosphor effectively detected level 1-3 structures of LFPs under ultraviolet irradiation, and ultimately detected LFPs in various daily life circumstances. These findings indicate that the SLTO:0.30Eu(3+) phosphor might be a viable option for w-LED lighting applications and LFPs visualization.
摘要：
A series of reddish-orange emitting Ca2InNbO6:Sm3+ (CINO:Sm3+) phosphors for white light-emitting diodes (w-LEDs) were synthesized using a high-temperature solid-state technique. The synthesized CINO:Sm3+ phosphors are pure phases with monoclinic structures. The optimal Sm3+ doping concentration is 0.02 mol, and concentration quenching is due to the dipole-dipole interaction. Upon 407 nm excitation, the as-prepared CINO:Sm3+ phosphors exhibited strong reddish-orange emission around 602 nm, attributed to the 4G5/2 -> 6H7/2 transition of Sm3+. Surprisingly, the CINO:Sm3+ phosphors revealed an abnormal thermal quenching (ATQ) phenomenon, and when the temperature of the phosphors was raised to 380 K, their emission intensity increased by more than 15%. The CINO:0.02Sm3+ phosphor had a high color purity (98.9%) and reddish-orange chromaticity coordinates (0.608, 0.388). Meanwhile, the manufactured w-LED demonstrated a good color rendering index (Ra = 93), decent CCT (5752 K), and Commission International de l ' Eclairage (CIE) chromaticity coordinates (0.327, 0.335). The experimental results demonstrated the su-periority of the CINO:Sm3+ phosphors in w-LEDs.(c) 2022 Elsevier B.V. All rights reserved.
期刊：
International Journal of Molecular Sciences,2022年23(21):13089- ISSN：1422-0067
通讯作者：
Lianwu Xie<&wdkj&>Deyi Yuan
作者机构：
[Zhong, Yujun; Shen, Dianling; Hu, Xiaopeng; Li, Zhiyang; Xie, Lianwu; Guo, Yaping] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Peoples R China.;[Yan, Yu; Xie, Lianwu] Cent South Univ Forestry & Technol, Coll Mat Sci & Technol, Changsha 410004, Peoples R China.;[Yuan, Deyi] Cent South Univ Forestry & Technol, Minist Educ, Key Lab Cultivat & Protect Nonwood Forest Trees, Changsha 410004, Peoples R China.
通讯机构：
[Lianwu Xie; Deyi Yuan] A;Authors to whom correspondence should be addressed.<&wdkj&>Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of Ministry of Education, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Authors to whom correspondence should be addressed.<&wdkj&>College of Material Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>College of Sciences, Central South University of Forestry and Technology, Changsha 410004, China
关键词：
Camellia spp. fruit shells;gallic acid;molecularly imprinted polymers;deep eutectic solvents;separation and purification
摘要：
To produce antioxidant substances from agricultural waste Camellia spp. fruit shells before their further utilization, gallic acid from five kinds of Camellia spp. fruit shells was separated on specific recognition by deep eutectic solvent molecularly imprinted polymers (DES@MIPs), which were prepared by bulk polymerization using gallic acid as the template and deep eutectic solvents (alpha-methylacrylic acid and choline chloride) as functional monomers. The optimized DES@MIPs were characterized by scanning electron microscopy, particle size analysis, nitrogen sorption porosimetry, elemental analysis, Fourier transform infrared spectroscopy, and thermal gravimetric analysis. The adsorptive behavior of gallic acid on DES@MIPs was also investigated. The results indicated that DES@MIPs were successfully prepared as mesoporous materials with average pore diameter of 9.65 nm and total pore volume of 0.315 cm(3) g(-1), and the adsorption behavior was multilayer adsorption and pseudo-second-order kinetics with the saturation adsorptive capacity of gallic acid reaching 0.7110 mmol g(-1). Although the content of gallic acid in five fruit shells was quite different, the purification recovery of gallic acid was high, ranging from 87.85-96.75% with a purity over 80%. Thus, the purification of gallic acid from Camellia spp. fruit shells could be realized feasibly using DES@MIPs with favorable economic and environmental benefits.
期刊：
Journal of Polymers and the Environment,2022年30(11):4863-4876 ISSN：1566-2543
通讯作者：
Yaping Guo<&wdkj&>Lianwu Xie
作者机构：
[Fan, Yajun; Zhong, Yujun; Shen, Dianling; Hu, Xiaopeng; Li, Zhiyang; Xie, Lianwu; Guo, Yaping] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Peoples R China.;[Yan, Yu; Xie, Lianwu] Cent South Univ Forestry & Technol, Coll Mat Sci & Technol, Changsha 410004, Peoples R China.
通讯机构：
[Yaping Guo; Lianwu Xie] C;College of Sciences, Central South University of Forestry and Technology, Changsha, China<&wdkj&>College of Sciences, Central South University of Forestry and Technology, Changsha, China<&wdkj&>College of Material Science and Technology, Central South University of Forestry and Technology, Changsha, China
摘要：
To achieve efficient adsorption and recycling of Cu2+ in wastewater, using Cu2+ as template ion, glutaraldehyde as crosslinker, three sodium alginate hydrogel beads including SA, SAC, and SAB beads were prepared by imprinting sol-gel method using sodium alginate (SA) with carboxymethyl cellulose (CMC) and beta-cyclodextrin (beta-CD) as different precursors, respectively. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to characterize and analyze morphology and composition change of the hydrogel beads, respectively. When the mass ratio of SA to CMC or SA to beta-CD reach 1:1, the SAC beads or SAB beads are nearly homogeneous sphere. Then the effects of pH, adsorption time, initial concentration of Cu2+, adsorbent dosage, and coexisting ions on the adsorption efficiency of three hydrogel beads were investigated. The results indicated that adding carboxymethyl cellulose and beta-cyclodextrin into skeleton of beads increased the toughness of the beads and improved the adsorption capacity of Cu2+. Compared to the saturated adsorption capacity 510 mg/g of Cu2+ on SA, the saturated adsorption capacity of Cu2+ on SAB and SAC reached 817 mg/g and 822 mg/g, respectively. And their adsorption efficiency for Cu2+ are over 95% at 25 degrees C with pH of 7, contact time within 350 min, adsorbent dosage of 4 mg/50 mL, and initial concentration of 5 mg/L. Thus, SAC and SAB beads could be used as adsorption material for detecting and removing Cu2+ from wastewater.
作者机构：
[Fan, Yajun; Zhang, Gui; Li, Jiawei; Xie, Lianwu; Guo, Yaping] Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Peoples R China.;[Zhang, Gui] Cent South Univ Forestry & Technol, Key Lab Digital Dongting Lake Basin Hunan Prov, Changsha 410004, Peoples R China.
通讯机构：
[Xie, LW; Zhang, G] C;Cent South Univ Forestry & Technol, Coll Sci, Changsha 410004, Peoples R China.
关键词：
Digital image colorimetry;Chemical analysis;Color space;Smartphone;Digital application
摘要：
Digital image colorimetry (DIC) on smartphone is regarded as a powerful, fast and low-cost analysis method to measure target analyte with color changes of digital image obtained by the built-in camera. We summarized the basic procedure of DIC, the color spaces (RGB, CMYK, HSB/HSL, CIE XYZ, L*a*b*, and YUV), the principal architectures (tools for capturing image, lighting conditions, and color quantification APPs and DIC APPs), and current status of DIC on smartphone in analysis of metals/heavy metals, herbicides, pesticides, antibiotics, biological and medical indicators, natural compounds, and bacteria/viruses. The advantages and disadvantages of DIC are also revealed. Nowadays, DIC on smartphone must be further refined with controlled geometry and standard lighting sources to become robust and reliable analytical procedures. And it will be improved in the near future with the continuous development of smartphones owing to the rapid development of smartphone's camera technology and the continuous optimization of related software.
摘要：
Red-emissive carbon dots (CDs) were synthesized by one-step hydrothermal technique using citric acid (CA), and urea in N,N-dimethylformamide (DMF) solution. The CDs has an average diameter of 2.3 nm, excitation/emission maxima at 553/606 nm, and a low photoluminescence quantum yield (4%). Fluorescence is weakly quenched by the ions Fe(3+), Hg(2+), Cu(2+), Co(2+), Zn(2+), Ca(2+), Ni(2+), and Pb(2+). After addition of cetyltrimethyl ammonium ion (CTAB), electrostatic interaction between negatively charged CDs and CTAB causes the CDs to self-aggregate. The formation of CD/CTAB increases the average particle diameter to around 13 nm and enhances the quantum yield to 24%. The hydrophobic segments of CTAB twined into a network structure can selectively trap Fe(3+) and then interact with surface groups of the CDs to cause quenching. The CD/CTAB nanoprobe enables fluorometric determination of Fe(3+) with a linear response in the 0.10-10 muM concentration range and a 0.03 muM limit of detection. The probe was utilized for determination of Fe(3+) in human serum samples, and satisfactory results were obtained. Graphical abstractSchematic representation of fluorometric analysis of Fe(III) ion by cetyltrimethyl ammonium ion (CTAB) mediated red emission carbon dots (CDs). The hydrophobic segments of CTAB twined into a network structure can selectively trap Fe(III) and then interact with surface groups of the CDs to cause quenching.
