Polyethyleneimine-Functionalized Carbon Nanotube/Graphene Oxide Composite: A Novel Sensing Platform for Pb(II) Acetate in Aqueous Solution

Abstract

Heavy metal pollution is posing a severe health risk on living organisms. Therefore, significant research efforts are focused on their detection. Here, we developed a sensing platform sensor for the selective detection of lead(II) acetate. The sensor is based on self-assembled polyethyleneimine-functionalized carbon nanotubes (PEI-CNTs) and graphene oxide films deposited onto gold interdigitated electrodes. The graphene-based nanostructure showed a resistive behavior, and the fabricated layer-by-layer film was used to detect Pb(II) acetate in an aqueous solution by comparison of three electrochemical methods: impedance spectroscopy, amperometry, and potentiometry stripping analysis. The results obtained from different methods show that the detection limit was down to 36 pmol/L and the sensitivity up to 4.3 μAL/ μmol, with excellent repeatability. The detection mechanism was associated with the high affinity of heavy metal ions with the functional groups present in the PEI-CNTs and GO, allowing high performance and sensitivity. The achieved results are important for the research toward integrated monitoring and sensing platforms for Pb(II) contamination in drinking water.

Hydrophobic polymer nano hybrid ternary composite electrode for nanomolar tracing of Cd2+ ions

“…28 Additionally, CNTs facilitate rapid electron transfer at the electrode-electrolyte interface, leading to enhancing electrochemical reactivity and reducing electrolyte impedance. 2,27,[29][30][31] These characteristics make CNTs highly attractive materials as surface modifiers in various electrochemical devices. [32][33][34] Molybdenum disulfide (MoS 2 ) having a prominent graphene-like 2D structure has gained significant interest in recent years.…”

“…A conductive component was of particular interest for electrochemical sensors 24,25 . Carbon nanotubes (CNTs) have emerged as highly promising candidates due to their affordability, excellent conductivity, ease of functionalization, large surface area, and impressive resistance to corrosion in various electrolytic environments 2,26,27 . The existence of carboxyl groups on the surface of CNTs facilitates nucleation and strong bonding with the sensing analyte 28 .…”

“…However, it has also brought about a range of environmental issues causing a significant threat to human health. [1][2][3][4][5] Among these issues, there is an increasing concern about water pollution, largely attributed to the existence of heavy metal ions (HMIs). [6][7][8][9][10][11] HMIs like Cd 2+ , Hg 2+ , Cr 2+ , and Pb 2+ are hard pollutants that resist biodegradation and tend to accumulate in organisms through ecological chains.…”

“…24,25 Carbon nanotubes (CNTs) have emerged as highly promising candidates due to their affordability, excellent conductivity, ease of functionalization, large surface area, and impressive resistance to corrosion in various electrolytic environments. 2,26,27 The existence of carboxyl groups on the surface of CNTs facilitates nucleation and strong bonding with the sensing analyte. 28 Additionally, CNTs facilitate rapid electron transfer at the electrode-electrolyte interface, leading to enhancing electrochemical reactivity and reducing electrolyte impedance.…”

Polyacrylonitrile/Reduced Graphene Oxide Free-Standing Nanofibrous Membranes for Detecting Endocrine Disruptors

“…More importantly, the nanofibrous membranes can be easily modified with conductive nanomaterials for improving sensitivity. In this regard, graphene-based materials have been widely combined with other materials to obtain nanocomposites with excellent performance in sensing applications. − Such high performance is generally achieved due to their high specific surface area, good electrical conductivity, and the presence of oxygen functional groups that can act as binding and analyte recognition sites. − To the best of our knowledge, the use of nanofibrous membranes modified with graphene-based materials as flexible and free-standing sensing platforms operating through electrical impedance has not been reported so far.…”