Sensitive Detection of Industrial Pollutants Using Modified Electrochemical Platforms

Abstract

Water pollution is nowadays a global problem and the effective detection of pollutants is of fundamental importance. Herein, a facile, efficient, robust, and rapid (response time < 2 min) method for the determination of important quinone-based industrial pollutants such as hydroquinone and benzoquinone is reported. The recognition method is based on the use of screen-printed electrodes as sensing platforms, enhanced with carbon-based nanomaterials. The enhancement is achieved by modifying the working electrode of such platforms through highly sensitive membranes made of Single- or Multi-Walled Carbon Nanotubes (SWNTs and MWNTs) or by graphene nanoplatelets. The modified sensing platforms are first carefully morphologically and electrochemically characterized, whereupon they are tested in the detection of different pollutants (i.e., hydroquinone and benzoquinone) in water solution, by using both cyclic and square-wave voltammetry. In particular, the sensors based on film-deposited nanomaterials show good sensitivity with a limit of detection in the nanomolar range (0.04 and 0.07 μM for SWNT- and MWNT-modified SPEs, respectively) and a linear working range of 10 to 1000 ppb under optimal conditions. The results highlight the improved performance of these novel sensing platforms and the large-scale applicability of this method for other analytes (i.e., toxins, pollutants).

Expanding the circularity of plastic and biochar materials by developing alternative low environmental footprint sensors

“…3a and b, it is possible to observe that the modification with biochar produced a dramatic improvement of the sluggish surface kinetics typical of bare electrodes (both SPEs and PET_SPEs) as demonstrated in our previous works. 12…”

“…3a and b, it is possible to observe that the modification with biochar produced a dramatic improvement of the sluggish surface kinetics typical of bare electrodes (both SPEs and PET_SPEs) as demonstrated in our previous works. 12 This is evidenced by the decrease in the generally high charge transfer resistance (R ct , diameter of the semicircle) of bare platforms compared to that of biochar-modified SPEs and PET_SPEs. Specifically, the calculated R ct values for bare SPEs and PET_SPEs were 1.8 ± 0.2Ω and 1.9 ± 0.2Ω, respectively, and achieved 10-fold lower values after the modification with biochar (i.e., 0.15 ± 0.01Ω and 0.17 ± 0.01Ω, for Bio-SPE and Bio-PET_SPEs, respectively).…”

“…10 Properly connecting the receptor-transducer coupling provides selectivity and sensitivity; nevertheless, various nano/materials, conducting polymers, and composites are frequently employed to functionalize the electrode transducer and enhance the analytical performance of the sensor. 11,12 Plastics are substituting glass, metals, and ceramics as substrates in screen-printing technology and for the development of wearable stretchy sensors, lab-on-a-chip, and point-of-care diagnostic tools. 9 The use of plastic materials in electrochemistry permits a greater degree of functional integration, including the introduction of wireless transmission modules, control and data acquisition instrumentation, and in-built power units, among others, and provides advantages over metallic and ceramic materials, including mild synthetic conditions, scalable and large-area processing, low operating temperature, and biocompatibility.…”

Two-Dimensional Non-Carbon Materials-Based Electrochemical Printed Sensors: An Updated Review

“…Compared to the recently published article on single- and multi-walled carbon nanotubes (SWCNTs and MWCNTs) modified SPE for the detection of quinone-based industrial pollutants, the proposed sensor by Neethipathi et al was inferior in terms of sensitivity. The SWCNTs and MWCNTs modified SPE had lower LOD values of 0.04 μM and 0.07 μM, respectively [ 113 ]. However, it must be noted that the comparison is established only on the sensitivity of the sensing materials for industrial pollutant detection in general.…”

A Deep Learning Approach to Organic Pollutants Classification Using Voltammetry

“…Indeed, these approaches have been shown to provide good sensing performance [ 5 , 6 , 7 ], while enabling the possibility of moving the analysis from the lab to in situ [ 8 ]. Furthermore, recently improved performance by modifying SPEs with 2D nanocarbon materials (e.g., carbon nanotubes or graphene nanoplatelets films [ 9 , 10 , 11 ]) was demonstrated.…”