Tripeptide Derivative-Modified Glassy Carbon Electrode: A Novel Electrochemical Sensor for Sensitive and Selective Detection of Cd²⁺ Ions

Abstract

A N-[(Benzyloxy)­carbonyl]-l-alanyl-l-prolyl-l-leucine-N-cyclohexylcyclohexanamine (Cbz-APL) tripeptide-coated glassy carbon electrode (GCE)-based sensor was used for sensitive and selective recognition of cadmium ions in environmental water. Detailed cyclic voltammetric and electrochemical impedance spectroscopic studies were performed to investigate the charge transfer and sensing activity of the developed electrochemical sensor. Square wave anodic stripping voltammetry (SWASV) was employed to further investigate the sensitivity, selectivity, validity, and applicability of the developed sensor. A sharp electrochemical signal of oxidized Cd at −0.84 V versus Ag/AgCl provides evidence for the higher sensing ability of Cbz-APL/GCE than bare GCE at −0.79 V. Moreover, on Cbz-APL/GCE, extraordinary low detection limits of 4.34 fM and linearity range of 15 nM to 0.1 pM with coefficients of correlation higher than 0.99 for Cd2+ were achieved. Besides, the influence of inorganic and organic interferents on the targeted analyte signals was examined, and high selectivity of Cbz-APL/GCE for Cd2+ ions was observed. Lastly, the validity and applicability of the developed electrochemical sensor for the detection of Cd2+ ions were checked in real water samples, and 100% recovery was obtained.

A Novel Electrochemical Sensing Platform for the Sensitive Detection and Degradation Monitoring of Methylene Blue

“…The limit of detection (LOD = 3 σ/m) and limit of quantification (LOQ = 10 σ/m) of the targeted analyte were evaluated from the calibration plot by applying IUPAC guidelines [47]. The standard deviation represented by σ was calculated by the current values (n = 11) of the blank solution at the peak position of the analyte [48]. The calculated limit of detection and limit of quantification of MB are 0.21 nM and 0.70 nM, respectively.…”

A designed miniature sensor for the trace level detection and degradation studies of the toxic dye Rhodamine B

“…, 3 σ / m and 10 σ / m respectively. 38 Where m is the slope of the linear calibration plot ( Fig. 6B ) and σ is the standard deviation of the blank solution.…”

“…The detection and quantication limits were calculated according to IUPAC guidelines i.e., 3s/m and 10s/m respectively. 38 Where m is the slope of the linear calibration plot (Fig. 6B) and s is the standard deviation of the blank solution.…”

Aminotetrazole-Functionalized SiO2 Coated MgO Nanoparticle Composites for Removal of Acid Fuchsin Dye and Detection of Heavy Metal Ions

“…To this unspiked sample, 4 μL of 0.2 M analyte solution was added, and the stripping current was recorded, which was designated as i spiked . The % recovery (% R ) was calculated using the following equation: , The parameter i known represents the stripping current from the calibration plot corresponding to 20 μM concentration of the analyte. Each measurement was performed three times to calculate the standard deviation.…”