Polyphenol oxidase-based electrochemical biosensors: A review.

/pdf/construction-of-amperometric-biosensor-modified-with-1hjneg7vgf.pdf

Construction of amperometric biosensor modified with conducting polymer/carbon dots for the analysis of catechol

Tea is a popular beverage all around the world. Tea composition, quality monitoring, and tea identification have all been the subject of extensive research due to concerns about the nutritional value and safety of tea intake. In the last 2 decades, research into tea employing electrochemical biosensing technologies has received a lot of interest. Despite the fact that electrochemical biosensing is not yet the most widely utilized approach for tea analysis, it has emerged as a promising technology due to its high sensitivity, speed, and low cost. Through bibliometric analysis, we give a systematic survey of the literature on electrochemical analysis of tea from 1994 to 2021 in this study. Electrochemical analysis in the study of tea can be split into three distinct stages, according to the bibliometric analysis. After chromatographic separation of materials, electrochemical techniques were initially used only as a detection tool. Many key components of tea, including as tea polyphenols, gallic acid, caffeic acid, and others, have electrochemical activity, and their electrochemical behavior is being investigated. High-performance electrochemical sensors have steadily become a hot research issue as materials science, particularly nanomaterials, and has progressed. This review not only highlights these processes, but also analyzes and contrasts the relevant literature. This evaluation also provides future views in this area based on the bibliometric findings.

/pdf/electrochemical-sensors-and-biosensors-for-the-analysis-of-1juiysa3.pdf

Electrochemical Sensors and Biosensors for the Analysis of Tea Components: A Bibliometric Review

Analytical performance of functional nanostructured biointerfaces for sensing phenolic compounds.

Carbon paste electrode modified with banana crude tissue CPE‐B, source of Polyphenol Oxidase enzyme for determination of catechol in green tea was developed. The electrochemical properties were assessed using square wave voltammetry in phosphate buffer 0.1 M, pH 7 using standard solutions of catechol. This biosensor exhibits sensitivity 2.32 µA/mg/L and detection limit 0.1 mg/L. Linearity range of the methods was from 1.4 to 15.7 mg/L with correlation coefficient 0.9990. Reproducibility of the signal obtained using 1.4 mg/L solution of catechol resulted with relative standard deviation 3.6% (n = 4). The biosensor was applied for the determination of catechol in green tea samples using two extraction methods: water extraction (s.d. ± 8.3 mg/L) and phosphate buffer solution extraction (s.d. ± 6.8 mg/L). The calculated recovery was between 89% and 92%, proving that the proposed CPE‐B biosensor can be an alternative analytical tool for determination of catechol in tea. PRACTICAL APPLICATIONS: In this study, it is reported the development of a carbon paste electrode modified with banana crude tissue (natural source of PPO enzyme), as alternative methods for determination of catechol in green tea sample using square wave voltammetry technique. In order to improve electroanalytical performance of CPEB, different parameters were optimized such as amount of modifier, pH of working solution, amplitude, frequency, and step potential. The real sample of green tea occasionally is taken in the market.

Determination of catechol in extract of tea using carbon paste electrode modified with banana tissue

Electrochemical determination of atenolol and propranolol using a carbon paste sensor modified with natural ilmenite

Comparative study of the environmental state of Ohrid and Prespa Lakes, Albania.

F enolik bilesiklerin belirlenmesi icin enzimatik bir karbon elektrot macunu gelistirilmistir. Elektrot malzemesi parafin ve canli ortamda polifenol oksidaz PPO iceren ham mantar doku ile birlikte tek dagilimli monodisperse grafit tozunun karistirilmasi ile hazirlanmistir. Bilesenleri arasindaki oran karbon - doku parafin , 0.1 M sodyum fosfat tamponu, pH 7, ve 50 mV/s tarama hizinda SCV Stare Case Voltammetry teknikleri kullanilarak arastirilmistir. Turev voltamogramlar biyosensor yanitini degerlendirmek icin kullanilir. Analitik performans karbon tozu granulometrisi ile yakindan ilgilidir. Karbon tozu granulometrisi 0,09-0,071 mm iken, arka akim ve hassasiyeti 1.57 mA / ppm ile ilgili olarak en iyi sonuclar elde edildi. Ayrica mantar govdesinin ayrilmis dort bolumunden alinan PPO aktivitesi incelenmistir. Enzimatik reaksiyonun kinetigi Michaels-Menten mekanizmasina gore sonuclanmistir. Biyosensor yaniti, farkli fenolik bilesiklere karsi test edilmistir. Hidrokinon icin biyosensor duyarliligi ile ilgili en iyi sinyal S = 2.04 mA / ppm , korelasyon katsayisi R2 = 0,9997 ve algilama siniri 0.7 ppm elde edilmistir ve diger calisilan bilesikler su sirada verilmektedir: hidrokinon> katekol > fenol> m-kresol> 4-klorofenol> p-kresol> 4-nitrofenol> 3-nitrofenol

/pdf/different-part-of-mushroom-tissue-used-as-modifier-in-carbon-224t4jxhdu.pdf

Different Part of Mushroom Tissue Used as Modifier in Carbon Paste Sensor

A modified glassy carbon electrode (Aufilm/GCE) using a gold film was constructed for determination\nof chromium(VI) in real water samples. A GCE was immersed in HAuCl4 solution (10-3 M) and the\nthin layer of gold was electrodeposited for 10 min at −0.4 V (vs. Ag/AgCl). Compared with only GCE,\na strong affinity between chromium and gold species was observed with an increase in Cr(VI) signal.\nThe type of supporting electrolytes, electrodeposition time, scan rate, pH, modulation time and the\nmodulation amplitude were optimized through differential pulse-anodic stripping voltammetry\n(DP-ASV). A calibration graph acquired using the accumulation time of 120 s with a sensitivity of 1.3\n× 10-2 μA/μgL-1 was linear in the range of 10-120 μg L-1. A low detection limit of 5.5 μg/L Cr(VI) and\na strong correlation coefficient R2 = 0.9971 were obtained under the optimal experimental conditions.\nSignals were reproducible and exhibited a relative standard deviation of ±4.5%. A modified sensor\nwas employed to determine the Cr(VI) content in the sewage water samples.

Nevila Broli

Papers

Determination of catechol in extract of tea using carbon paste electrode modified with banana tissue

Electrochemical determination of atenolol and propranolol using a carbon paste sensor modified with natural ilmenite

Comparative study of the environmental state of Ohrid and Prespa Lakes, Albania.

Different Part of Mushroom Tissue Used as Modifier in Carbon Paste Sensor

Electrochemical Behaviour of Gold Thin Film GlassyCarbon Electrode for Determination of Chromium(VI)