Layer-by-layer hybrid films of phosphate cellulose and electroactive polymer as chromium (VI) sensors

Study on self-assembled monolayer of functionalized thiol on gold electrode forming capacitive sensor for chromium(VI) determination

“…The experiments carried out demonstrated that reducing the number of measuring cycles recorded in supporting electrolyte allowed to increase the sensor sensitivity and made possible determination of Cr(VI) at lower concentration levels, in nanomolar range, in comparison with those reported formerly [27]. 2 × 10 −10 (buffer) 3 × 10 −10 (seawater) [29] [30]…”

“…For this purpose, the formula LOD = t α, f • s was employed, where t α, f was the critical Student's t value read for the significant level α = 0.1 and f degrees of freedom for n measurements (f = n − 1), and s was the standard deviation of the obtained results [42]. The calculation performed based on ten analyses carried out for 1 nmol• Comparing the presented sensor to other electrochemical sensors designated for Cr(VI) determination (see Table 3), it can be noticed that in this case, linear response range was better than obtained for the sensors based on hybrid films of phosphate cellulose and electroactive polymer [29], polyaniline/graphene quantum dot-modified screen-printed carbon electrode [31] and screen-printed carbon electrode modified with gold nanoparticles [32]. The developed sensor exhibited lower limit of detection in comparison with all reported sensors except for vibrating silver amalgam microwire electrode demonstrating similar LOD values [30].…”

“…The second form, Cr(VI), has an undesirable effect on the lungs, liver, and kidneys. The examples of electrochemical chromium(VI) determination include the use of a glassy carbon electrode modified with silicomolybdate doped polypyrrole film [28], the preparation of hybrid and electroactive thin films containing microcrystalline cellulose (MC), or MC modified with a phosphate group (PC) in conjunction with polyaniline (PANI) and poly(vinyl sulfonic acid) (PVS) by the layer-by-layer technique [29] or determination in estuarine waters by catalytic cathodic stripping voltammetry using a vibrating silver amalgam microwire electrode [30]. The determination of Cr(VI) employing the screen-printed carbon electrode (SPCE) modified with the use of organic compound (PANI) and graphene quantum dot [31] or inorganic nanoparticles like AuNPs [32] have been reported.…”

An overview of sensors and sensing materials for heavy metals in aqueous environments

“…Potentiometric Aravind and Mathew [91] Cr +6 Poly(vinyl sulfonic acid) / polyaniline (PVS/PANI) 4.83 μM -1.5 Room temp. Potentiometric Teixeira et al [92] Cr +6 Amidoximated polyacrylonitrile fibres (AO-PANF) 10 mg/L 60 min 3.0 Room temp. Spectrographic Bouchoum et al [93] Cu +2 Thiosemicarbazone (5%) PVC (34%) dibutyl phthalate (DBP) (60%)…”

Recent Advances in Electrochemical Monitoring of Chromium

“…Layer by layer technique in conjunction with polyaniline and poly(vinyl sulfonic acid) (PVS) was also proposed for the elaboration of thin films fabricated from non-modified microcrystalline cellulose (MC) or MC modified by phosphate group (PC) which improves the conductivity and the stability of PANI in presence of the metal [ 108 ]. The prepared sensor (PVS/PANI(PC)/ITO) in combination with square wave voltammetry showed the ability for Cr(VI) monitoring linearly from 759.2 to 3120 µg·L −1 .…”