Facile Conversion of Toxic Cigarette Butts to N,S-Codoped Carbon Dots and Their Application in Fluorescent Film, Security Ink, Bioimaging, Sensing and Logic Gate Operation

Rajkumar Bandi; Neela Priya Devulapalli; Ramakrishna Dadigala; Bhagavanth Reddy Gangapuram; Veerabhadram Guttena

doi:10.1021/acsomega.8b01743

Facile Conversion of Toxic Cigarette Butts to N,S-Codoped Carbon Dots and Their Application in Fluorescent Film, Security Ink, Bioimaging, Sensing and Logic Gate Operation

ACS Omega. 2018 Oct 31;3(10):13454-13466. doi: 10.1021/acsomega.8b01743. Epub 2018 Oct 18.

Authors

Rajkumar Bandi¹, Neela Priya Devulapalli², Ramakrishna Dadigala¹, Bhagavanth Reddy Gangapuram^{1

3}, Veerabhadram Guttena¹

Affiliations

¹ Department of Chemistry, Osmania University, Hyderabad 500007, Telangana, India.
² Environmental Consultancy Division, Ramky Enviro Services Private Limited, Ramky Grandiose, Gachibowli, Hyderabad 500032, India.
³ Department of Chemistry, PG Center Wanaparthy, Palamuru University, Mahabubnagar 509001, Telangana, India.

Abstract

The present work is emphasized on converting toxic cigarette butts (CBs) into highly fluorescent N,S-codoped carbon dots by a facile hydrothermal approach and exploring their multiple applications. The as-produced carbon dots (CBCDs) exhibited bright and stable fluorescence with a quantum yield of 26% and used as a label-free probe for "on-off-on" sequential detection of Fe³⁺ and ascorbic acid (AA). The fluorescence of CBCDs can be significantly quenched by Fe³⁺ ions through static quenching and restored upon the subsequent addition of AA due to the reduction of Fe³⁺ to Fe²⁺ by AA. This nanoprobe presented great selectivity and excellent sensitivity to Fe³⁺ and AA with a detection limit of 0.13 and 0.2 μM, respectively. Furthermore, the nanoprobe was extended to biosystem (intracellular detection) and successfully applied for the detection of Fe³⁺ in real water (tap, bore, and pond) and AA in biological samples (human urine and serum). In addition, we have constructed an IMPLICATION logic gate based on these unique sensing characteristics. The "visible-invisible" and "UV-visible" property explored their use as invisible ink for security applications. Furthermore, highly photostable fluorescent polymer films were prepared by incorporating CBCDs in poly(vinyl alcohol). It is anticipated that the strong and stable fluorescence emission nature of these films might find direct or indirect applications in various optical/optoelectronic devices, ranging from fluorescent displays to light-emitting diodes.