Theoretical and experimental findings regarding the electroanalysis of dienestrol in natural waters using a silver nanoparticles/single-walled carbon nanotubes-based amperometric sensor

The Role of Silver Nanoparticles in Electrochemical Sensors for Aquatic Environmental Analysis

“…In contrast, one-electron transfer was demonstrated in nitrite sensing with a nanosilver–polymer composite (chitosan, PEDOT:PSS) [ 142 ], and also with an AgNPs-MWCNTs hybrid platform [ 74 ]. AgNP/SWCNT/CPE was used to detect DNL by the irreversible oxidation of phenolic groups to (semi)quinone species [ 84 ]. The overall chemical–electrochemical mechanism involves a transfer of two protons and two electrons, but the final product depends on the applied potential and the electrode modifier used.…”

“…3D MWCNTs, especially functionalized by acid treatment, possess excellent thermal and electrical conductivity, which, combined with their large surface area, significantly improves the catalytic properties for the oxidation of ammonium and nitrite species [ 74 , 138 , 144 ], and the detection of phenolic compounds [ 80 , 152 ] in real water matrices. In only one scientific paper, SWCNTs were used in conjunction with AgNPs as a sensing surface for the quantification of the synthetic estrogen dienestrol in river water [ 84 ]. Another approach to increase the sensitivity is to use the CPs in the nanosilver-based sensing hierarchy in the form of an AgNPs@p-1,8-DAN layer [ 73 ] or an AgNPs/CB/PEDOT:PSS film [ 163 ] built over disc GCE, or ternary hybrid structures of nanosilver on the (r)GO platform with PPy [ 133 ] or PANI [ 134 ].…”

“…Therefore, to preserve the unique thermal and electrical properties of AgNPs, significant progress has been made towards the synthesis of AgNPs with controllable morphology, dimensions, surface charge, and physicochemical properties. To improve their sensing properties, AgNPs are often integrated into nanocomposite materials, e.g., by alloying with some another metal [ 83 ], embedded into single- [ 84 ] or multiwalled [ 74 ] carbon nanotubes, anchored on functionalized graphene (oxide) platforms [ 85 , 86 ], modified to form multifunctional ternary systems [ 87 ], or deposited in the form of a thin film on the electrode surface [ 88 ].…”

“…A composite of AgNPs- and SWCNTs-modified CPE exhibited attractive properties for the determination of the synthetic estrogen dienestrol (4-[4-(4-hydroxyphenly)hexa-2,4-dien-3-yl]phenol; DNL) [ 84 ]. In order to find the reaction medium with the most pronounced synthetic estrogen electrooxidation signal, different buffer and acid solutions (pH range 2–12) were tested in a conventional three-electrode system, using CV at scan rate of 50 mV s −1 .…”

Recent advances in silver nanoparticle-based electrochemical sensors for determining organic pollutants in water: a review

“…The incorporation of AgNPs with AuNPs at a gold electrode for superior electrical conductivity was established to assess ciprofloxacin through its irreversible oxidation via two-electron and two-proton transfer 135 . Furthermore, AgNPs/SWCNT/CPE was used to detect dienestrol through the oxidation of phenolic groups to semiquinone structures via two-electron and twoproton transfer 172 . For detecting 5-fluorouracil, porphyran-AgNPs/CPE was used for drug oxidation via one-proton and oneelectron transfer 173 .…”