JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2020
·
IF 3.807
Gengxin Hu,Nanxi Li,Yuwei Zhang,Hong Li
The electrochemical oxidative quinone-functionalization of tryptophan (Trp) residues, and the proton-coupled electron transfer properties between quinonized Trp (Trp=O) and its re-reduced species (Trp-OH) are investigated for potentiometric pH sensors. The Trp=O/Trp-OH couples are assembled on a graphite electrode using multiple cyclic voltammetry, and exhibit a pair of well-defined redox peaks at redox potential of 0.090 V (vs. SCE) at pH 7.0 and 298 K. The proton-coupled electron transfer properties of Trp=O/Trp-OH couples are dependent on electrode substrate material, incubation temperature and pH values, and Trp residue sources including amino acid, peptide and protein. The Trp=O/Trp-OH-based surface-confined exothermic electrode reaction rates show a decrease with increasing incubation temperature from 283 to 323 K at pH 5.0. Both of redox peak potential and open-circuit potential under optimum conditions have a good linear pH dependence between 1.0 and 12.0 with sensitivity of more than 52 mV pH −1 and relative standard derivation of 1.5%. The proposed potentiometric pH sensor has significant advantages of low cost, good stability and reproducibility, and strong anti-interference ability. The present study shows a new approach to endow Trp, Trp-containing peptides and non-conjugated proteins with analogous proton-coupled electron transfer performance to prosthetic groups of quinoproteins for monitoring pH changes in milk samples.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PAPERS
·
2019
·Vol. 74
·期 6
·1831-1838
·
IF 1.246
Cai Zhifeng,Zhang Caifeng,Jia Kang
A fast, simple, green and low-cost synthesis method in aqueous solution was successfully established for the preparation of l -tyrosine protected Cu nanoclusters (Cu NCs). Subsequently, the as-prepared Cu NCs was characterized by UV–vis absorption spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). It exhibited good water solubility, excellent photostability and high stability toward high concentration of sodium chloride. The Cu NCs revealed maximum excitation and emission peaks at 430 and 477 nm, respectively. Importantly, the Cu NCs showed a rapid response, a liner relation over the pH ranges from 5.02 to 11.92 and could be repeated for five consecutive cycles without fluorescence decay. Further, the as-prepared Cu NCs was applied for the determination of pH value in water samples. Simultaneously, all above features showed that l -tyrosine protected Cu NCs had great potential for sensing of pH in biological field.
研究领域:
生物化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yi Tian,Yunlong Yue
To improve the photoluminescence (PL) and increase photostability of carbon dots (CDs), phosphorus doped CDs with bright green emitting were prepared using (NH 4 ) 2 HPO 4 and m-phenylenediamine (MPD), and terephthalic acid (TA) via a solvothermal synthesis. Compared to undoped CDs (M−CDs), the PL efficiency of P-doped sample (M−6 %P-CDs) created using optimized conditions was improved from 55.1 to 73.9 %. These bright CDs were incorporated in films to test the stability, in which the photostability in liquid and polymer films were improved by 6 and 37 %, respectively. Namely, it is found that P affected the functional groups of on the surface and inside CDs. Phosphorus promoted the dehydration condensation reaction of precursors, increased the structural defects of the CDs, separated the sp 2 structural domains, and retained more oxygen-containing functional groups. In the case of o-phenylenediamine (OPD) instead of MPD, the PL efficiency of P-doped CDs was decreased. This is ascribed to P impeding the polymerization process of OPD. These CDs were used for pH and Cr(VI) ion sensors. P-doping improved the sensitivity of CDs to pH and Cr(VI). The pKa value of sample M−6 %P-CDs was 8.32 which was much lower compared with undoped one (∼1.97). Moreover, P-doped CDs revealed significantly enhanced sensitivity response to Cr(VI). The detection range and detection limit of M−6 %P-CDs for Cr(VI) was 1–130 μM and 0.59 μM, respectively. These results are crucial for the preparation and applications of CDs.
研究领域:
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICA CHIMICA ACTA
·
2025
·
IF 6
Meihui Gao,Xianjing Zhang,Shiqi Li,He Gao,Xinyu Li,Dongyuan Xu,Longbin Xu
Background Wearable pH sensors have emerged as promising tools for real-time health monitoring, particularly for sports and clinical applications, due to their ability to monitor key physiological indicators such as sweat pH. Sweat analysis provides valuable insights into metabolic processes and physical exertion. However, the development of flexible, stable, and highly sensitive sensors for accurate sweat pH detection remains a challenge. Conductive polymer such as polyaniline (PANI), have gained attention due to their unique properties, but further improvements in mechanical flexibility and sensor performance are needed to fully realize their potential for wearable biosensing applications. Results We present a boric acid-functionalized PANI-ABA/PA hydrogel, synthesized via electrochemical deposition, where boric acid plays a crucial role in crosslinking the rigid PANI material into a flexible, porous grid structure. This crosslinking improves the mechanical properties of the hydrogel while enhancing its ion-exchange capacity, leading to greater sensitivity and selectivity for H + ions. PANI-ABA/PA hydrogel exhibits super-Nernstian behavior (77.80 mV pH −1 ) across the physiological pH range (3.00–10.00), with rapid response times, minimal temperature drift, and excellent repeatability. Moreover, the hydrogel exhibits outstanding antifouling properties, ensuring consistent performance even in dynamic environments. Real-time human subject testing confirms the sensor's ability to accurately monitor sweat pH during physical activity, providing reliable and real-time data. These results highlight the promising potential of the PANI-based hydrogel for wearable biosensors in health monitoring. Significance and novelty This study highlights the role of boric acid in facilitating the formation of a crosslinked PANI-based grid structure, which improves the sensor's performance in wearable applications. Enhanced sensitivity, stability, and mechanical flexibility make this smart wearable sensor a promising candidate for continuous, non-invasive health monitoring. It opens new opportunities for real-time athletic performance tracking, personalized healthcare, and disease diagnostics, positioning it as a leading technology for future wearable health-monitoring systems.
研究领域:
生物医学工程
·
材料科学
·
可穿戴设备
✓ 已验证
产品关联
DOI
PubMed
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2018
·
IF 2.975
Lei Lei,Hengchang Ma,Jiawei Lv,Tao Wang,Yuan Yang,Pei Yin,Ziqiang Lei,Yanfang Qin,Yucheng Ma,Wenhuan Yao
Materials hybrided by organic and inorganic partners via chemical bonds formation are able to display stable and multi-functional behaviors. Then, the versatile sensing platform could be established depending on their specific chemical and physical properties. In this research paper, we prepared the fluorescence materials (POSS-PDB and POSS-NTB) by a simple method. Among of them, POSS-NTB was verified as a mesoporous material with a narrowed pore diameter around 17 nm and the large Brunauer-Emmett-Teller (BET) surface area of 227 m 2 /g. Then, the solid powder of POSS-NTB was selected and evidenced as effective gas sensor toward CO 2 , N 2 and O 2 at 273 K under 1 atm pressure. Additionally, these fluorescence materials could be successfully applied as a pH sensor in the solution phase. Through combining biocompatible POSS and fluorescent molecules, POSS-NTB could enter into the cells and aggregate in the cytoplasm successfully.
研究领域:
材料科学
·
生物医学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Yanling Feng,Yufei Liu,Chen Su,Xinghu Ji,Zhike He
Silicon nanodots (SiNDs) are currently appealing to extensive studies due to their low toxicity and unique optical and electrical properties. In this work, we obtained label-free SiNDs via a facile hydrothermal method. The approach offers advantages in terms of cheap reactants, easy operation and a short time. The quantum yield (QY) of the SiNDs is up to 32.8%, and the as-prepared nanoparticles exhibit strong fluorescence (FL), higher photostability and obviously longer FL lifetime. More importantly, these label-free SiNDs can be used as a highly sensitive pH sensor, which FL respond rapidly to pH fluctuations and reveal a good linear relationship. Also, a superior pH-reversibility was demonstrated. Different salt ions show a little influence on the pH-responsive behavior. The pH of real water samples were tested on the basis of the proposed SiNDs sensor and the results are satisfactory. Further, traditional SiNDs with Si H or Si C surfaces make them less water-soluble or sensitive to the pH. Whereas, our SiNDs feature amino-terminated surface and these amino groups are conducive to the pH sensitivity. In a word, this new, cheap, low-toxic, and effective fluorescent pH sensor based on label-free SiNDs would be a promising candidate in biological field.
研究领域:
生物化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS
·
2018
·Vol. 18
·期 10
·3195
·
IF 2.475
Jianxin Zhang,Lei Zhou
Making use of the sol-gel technique, an optical pH sensor was prepared, which was made from an organic carrier with four indictors including congo red, bromophenol blue, cresol red, and chlorophenol red, cross-linked by tetraethyl orthosilicate (TEOS) and cellulose acetate. The actual detection range of the optical pH sensor is 2.5–11.0. The optimal ratio of ethyl orthosilicate, absolute ethanol, deionized water, and hydrochloric acid in glue precursor of the sensor-sensitive membrane was explored. The orthogonal experiment was designed to optimize the dosage of cellulose acetate,N,N-dimethylformamide (DMF), indicator, hydrochloric acid, and precursor glue in preparing the sensor-sensitive membrane. The linearity, measurement accuracy, repeatability, stability, and response time of the prepared pH sensor were tested. The measurement results were analyzed using a support vector machine and linear regression. The experimental results show that the optical pH sensor has a measurement accuracy of up to 0.2 pH and better stability and repeatability than the traditional pH glass electrode.Keywords:sol-gel technique;optical pH sensor;indicator;sensor-sensitive membrane
研究领域:
材料科学
·
化学传感器
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2023
·Vol. 170
·期 3
·037511
·
IF 3.9
Qiang Zou,Xiaole Wang,Qi Su,Tao Xue,Kuibo Lan
PH sensors are widely used in food processing, health monitoring, water quality monitoring, and many other fields. The pH sensor applied in the health monitoring field can realize the real-time measurement of human health information and timely prevent the occurrence of diseases by improving people's health levels. However, these sensors have some challenges in body fluid collection and temperature compensation. Here, we developed a pH sensor based on an extended-gate field-effect transistor (EGFET) with microfluidic channels and a temperature sensor to overcome these challenges. The sensor is prepared using a low-cost, solution-based process in which a temperature sensor is used for body temperature measurement and temperature compensation, and a microfluidic channel is used for body fluid collection. This pH sensor can measure both body temperature and pH of body fluid, where the temperature coefficient of resistance (TCR) of the temperature sensor is up to 5.17%, and the measurement result of body temperature is only 0.17 ℃ different from that of the gold standard. The pH sensitivity is 58.41 mV pH−1, and the pH value is only 0.066 deviating from the standard pH value. The sensor is expected to be used on a large scale in the applications of wearable health monitoring.
研究领域:
生物医学工程
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Yujian Bai,Rui Zhu,Jie Zhao,Guofeng Cui
A polyaniline pH sensor with super-Nernstian sensitivity (>59.12 mV/pH) was obtained through acid doping. After preparing polyaniline sensor by potentiostatic electropolymerization, the electrochemical property of sensor can be modulated by adjusting acid doping formulas. The result shows that when using doping solution containing 2.2 g/L sodium dihydrogen phosphate and 5 g/L sodium chloride at pH = 6, the polyaniline sensor exhibits a linear super-Nernstian behavior (−69.31 ± 1.66 mV/pH) in PBS buffer (pH 5.00 ∼ 9.00). We observed that the surface of electrode has a three-dimensional network structure which can greatly increase the surface area of the sensing film, thus improving the conductivity and the sensitivity of the senor. The mechanism of acid doping is revealed: phosphate and polyaniline form salt, which makes polyaniline change from insulator to metal state and improves the conductivity. This is one important reason for its super-Nernstian behavior. In order to better understand this behavior, a new super-Nernstian model is established. The parameter 1/r > 1 is introduced to represent the acid doping index of the sensor, which directly affects the sensitivity of the film. According to the formula, super-Nernstian behavior of pH sensor can be mathematically modeled. This investigation yields a consistently stable super-Nernstian pH sensor while providing enhanced insights into its super-Nernstian characteristics and underlying mechanisms.
研究领域:
材料科学
·
电化学
·
传感技术
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Yan Wang,Liyuan Zhao,Aojie Xu,Lei Wang,Lingli Zhang,Shuangqiang Liu,Yongjun Liu,Hanyang Li
We report a liquid crystal (LC) microdroplet-based pH sensor and explore its application for detecting enzymatic reactions in penicillinase. Nematic LC 4-cyano-4'-pentylbiphenyl (5CB) microdroplet, doped with 4'-pentyl-biphenyl-4-carboxylic acid (PBA), is produced in phosphate buffer solution (PBS) with a tapered capillary microtube connected to a syringe pump. The PBA-doped 5CB microdroplets exhibit configuration transitions from bipolar to radial as PBS pH values increase from 5.7 to 6.0. These pH-induced changes in optical appearance are experimentally verified and attributed to the deprotonation of PBA at the aqueous/LC interface. We also examine the feasibility of the PBA-doped 5CB microdroplets as optical microcavities of whispering gallery modes (WGMs). Typical WGM lasing emission is observed in micrometer-sized microdroplets under a pulse laser pump. The WGM spectrum from the microdroplet responds to pH variations, reflecting as a spectral redshift as the pH decreases. The PBA-doped 5CB microdroplet can be successfully exploited accordingly for detecting enzymatic reactions in penicillinase. We demonstrate that the detectable shifts in WGM spectra associated with the microdroplet configuration transitions can serve as an indicator of the H + released from the enzymatic reaction.
研究领域:
生物化学
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
LUMINESCENCE
·
2020
·Vol. 36
·期 1
·28-34
·
IF 1.855
Fan Zheng,Jun Guo,Abdul Jamil Khan,Pandeng Miao,Feng Zhang
Fluorescent nanostructures have been widely applied to biomedical researches and clinical diagnosis such as biolabeling/imaging/sensing and have even acted as therapy reagents. Peptide-based fluorescent nanostructures attract recent interest from biomedical researchers. Inspired by the natural existence of GHK-Cu complex with a growth factor-like effect in human blood, here we have developed a novel approach for designing nanosensors through the co-assembling of two kinds of biomolecules. By making best use of both π-π stacking between carbon rings and the easy-oxidation property of an important transmitter molecule, dopamine (DA), we successfully built up a supersensitive and robust fluorescent pH nanosensor by co-assembling oxidized DA (DA ox ) with a tripeptide GHK. The GHK-DA ox nanostructures have a quantum yield of 20.82%, which might be the brightest one among all the current co-assembling structures merely through unmodified biomolecules. We envision this approach could open a new avenue for not only hybrid nanostructure construction, but also may inspire the bioengineering of in vivo luminescent probes.
研究领域:
生物医学
·
纳米技术
·
化学传感
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Lei Wei,Guoqing Fang,Zhongwen Kuang,Lin Cheng,Huaping Wu,Daoyou Guo,Aiping Liu
Skin-mounted microfluidics devices have shown distinct advantages in sweat collection and analysis platform due to their multiple sweat treatment including sample collection, flow control, storage, analysis and expelling by special design in microfluidic networks. However, the fabrication of most reported wearable microfluidic devices with mechanical flexibility and elasticity mainly rely on soft-lithography technology whose implementation is limited by necessitating access to resource-intensive laboratory and costly facilities. Herein, we propose an accessible, low-cost fabrication and integration scheme, which renders flexible microfluidic architecture capable of performing reliable sweat collection and sensing. We utilize low-cost 3D-printing technology to rapidly yield positive mold of facile printable material (malt syrup) for personalized customization of microfluidic channels . An ingenious approach is also proposed to encapsulate microfluidic channel layer and integrate pH sweat sensor into the microfluidic device for dependable sweat collection and pH analysis. The proposed fabrication strategy of flexible and stretchable epidermal microfluidic sensor represents a low cost, reachable alternative to recently prevailing soft-lithography method, and hence significantly reduces the threshold of microfluidic development and manufacture.
研究领域:
生物医学工程
·
微流控技术
·
可穿戴设备
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）