Determination of organophosphorus compounds in water and food samples using a non-enzymatic electrochemical sensor based on silver nanoparticles and carbon nanotubes nanocomposite coupled with batch injection analysis

• Published in: Talanta (Oxford) Vol. 246; p. 123477
• Main Authors: Porto, Laís Sales, Ferreira, Lucas Franco, Pio dos Santos, Wallans Torres, Pereira, Arnaldo César
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.08.2022
• Subjects: Batch injection analysis; Chlorpyrifos - analysis; Diazinon - analysis; Electrochemical Techniques - methods; Electrodes; Functionalized carbon nanotubes; Graphite - chemistry; Malathion; Metal Nanoparticles - chemistry; Multiple pulse amperometry; Nanocomposites; Nanotubes, Carbon - chemistry; Organophosphorus Compounds; Pyrolytic graphite electrode; Silver - chemistry; Silver nanoparticles; Water - analysis; Organophosphorus compounds; Functionalized carbon nanotubes; Pyrolytic graphite electrode; Multiple pulse amperometry; Batch injection analysis; Silver nanoparticles
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2022.123477

This work presents, for the first time, a fast and highly sensitive electrochemical method for determination of three organophosphorus compounds (OPs), diazinon (DZN), malathion (MLT), and chlorpyrifos (CLPF), using a modified pyrolytic graphite electrode (PGE) coupled to batch injection analysis system with multiple pulse amperometric detection (BIA–MPA). The PGE was modified by a nanocomposite based on functionalized carbon nanotubes (CNTf) and silver nanoparticles (AgNPs). The OPs samples were directly analyzed on the modified working electrode surface by BIA-MPA system in Britton-Robinson (BR) buffer 0.15 mol L−1 at pH 6.0. The MPA detection of DZN, MLT and CLPF was performed using two potential pulses, which were sequentially applied on modified PGE at −1.3 V (100 ms) and +0.8 V (100 ms) for selective determination of these three OPs and working electrode cleaning, respectively. Under optimized conditions, the sensor presented a linear range of 0.1–20 μmol L−1 for DZN, 1.0–30 μmol L−1 for MLT and from 0.25 to 50 μmol L−1 for CLPF. The limits of detection (LOD) and quantification (LOQ) of 0.35 and 1.18 μmol L−1 for DZN, 0.89 and 2.98 μmol L−1 for MLT, and 0.53 and 1.78 μmol L−1 for CLPF were obtained. The proposed method exhibited high sensitivity of 0.068, 0.030 and 0.043 mA L μmol−1 for DZN, MLT and CLPF detection, respectively. Furthermore, the BIA-MPA system provided an analytical frequency of 71 determinations per hour for direct determination of these OPs in water and food samples. The modified PGE coupled to BIA-MPA system showed a high stability of electrochemical response for OPs detection with relative standard deviation (RSD) of 1.60% (n = 20). The addition-recovery studies of the proposed method were carried out in tap water, orange juice, and apple fruit real samples, which showed suitable recovery values between 77 and 124%. The analytical performance of the developed sensor provides an attractive alternative method for OPs determination with great potential for a fast and sensitive application in contaminated samples with these pesticides. [Display omitted] •Pyrolytic graphite electrode was modified with functionalized carbon nanotubes and silver nanoparticles.•The sensor was coupled with BIA system with MPA detection for diazinon, malathion, and chlorpyrifos determination.•LOD of 0.354, 0.894 and 0.533 μmol L−1 were obtained for DZN, MLT and CLPF, respectively.•An analytical frequency of 71 determinations per hour was obtained.•The sensor application was effective for organophosphorus determination in tap water, orange juice and apple samples.