Highly Selective and Rapid Naked-Eye Colorimetric Sensing and Fluorescent Studies of Cu²⁺ Ions Derived from Spherical Nanocellulose

Abstract

Nanocellulose has emerged as the most promising sustainable nanomaterial to develop cost-effective smart materials for various applications with consequential positive environmental impact. In the present study, we report spherical nanocellulose (SNC) modified with diethylenetriamine (DETA) and/or ethanolamine (EA) (SNC-DETA, SNC-EA, and SNC-DETA-EA) as Cu2+ ion sensors. Structure dependence of the sensing properties is the highlight of this work, as SNC-DETA-EA and SNC-DETA showed colorimetric naked-eye and fluorescent activity, with the former showing the same at very low ion concentrations with high selectivity, whereas SNC-EA lacked the same. The solution color changed rapidly to deep blue, and the fluorescence intensity was quenched when the ion concentration increased in the range 0.5–100 ppm, thus facilitating dual-channel ion detection. SNC-DETA-EA showed 1.03 ppm or a 1.622 × 10–5 M limit of detection and high Cu2+ ion uptake with maximum Langmuir capacity (q m) of 212.76 mg/g.

A Colorimetric Test to Differentiate Patients Infected with Influenza from COVID‐19

“…Other colorimetric sensors detect Cu 2+ using nanocellulose or Hg 2+ using GNPs, and DNAzymes have not yet been used to detect SARS‐CoV‐2 but were similarly not evaluated using environmental samples. [ 22,23 ] These colorimetric tests have been successful when detecting pure or spiked samples, but the challenge arises when clinical samples are used.…”

Nanocellulosics: Benign, Sustainable, and Ubiquitous Biomaterials for Water Remediation

“…133 It was further reported that spherical NC (SNC) was modified with diethylenetriamine (DETA) and/or ethanolamine (EA) (i.e., SNC−DETA and SNC−DETA−EA) to develop a highly selective and rapid sensor for Cu ions (Cu 2+ ), visible with the naked eyes, via colorimetric sensing and fluorescence. 134 The study demonstrated that the SNC−DETA−EA exhibited a distinctive structure−property relationship through these well-defined selective colorimetric and fluorometric sensing characteristics toward Cu 2+ . Therefore, it was possible to observe the fluorescent quenching behavior upon the addition of Cu 2+ ions even at low concentrations with the naked eye (Figure 9).…”

“…Therefore, it was possible to observe the fluorescent quenching behavior upon the addition of Cu 2+ ions even at low concentrations with the naked eye (Figure ). Moreover, this biocomposite sensor demonstrated good tolerance to pH variations, in addition to the added advantages of recyclability and reversibility …”

“…This developed bionanocomposite demonstrated suitable optical sensing for CN – at low detection limits of about ∼0.015 μg mL –1 in water . It was further reported that spherical NC (SNC) was modified with diethylenetriamine (DETA) and/or ethanolamine (EA) (i.e., SNC–DETA and SNC–DETA–EA) to develop a highly selective and rapid sensor for Cu ions (Cu 2+ ), visible with the naked eyes, via colorimetric sensing and fluorescence . The study demonstrated that the SNC–DETA–EA exhibited a distinctive structure–property relationship through these well-defined selective colorimetric and fluorometric sensing characteristics toward Cu 2+ .…”

“…Schematics representing the naked-eye observation of the fluorescent activity of SNC–DETA–EA in the presence of copper ions. Distinguishable selectivity for Cu 2+ and reversibility of the activity are evident . Photography courtesy: Ram, B.; Jamwal, S.; Ranote, S.; Chauhan, G. S.; and Dharela, R. Reprinted with permission from Ram, B.; Jamwal, S.; Ranote, S.; Chauhan, G. S.; and Dharela, R. Highly selective and rapid naked-eye colorimetric sensing and fluorescent studies of Cu 2+ ions derived from spherical nanocellulose.…”