Nanosensors Based on Structural Memory Carbon Nanodots for Ag+ Fluorescence Determination

Abstract

Ag+ pollution is of great harm to the human body and environmental biology. Therefore, there is an urgent need to develop inexpensive and accurate detection methods. Herein, lignin-derived structural memory carbon nanodots (CSM-dots) with outstanding fluorescence properties were fabricated via a green method. The mild preparation process allowed the CSM-dots to remain plentiful phenol, hydroxyl, and methoxy groups, which have a specific interaction with Ag+ through the reduction of silver ions. Further, the sulfur atoms doped on CSM-dots provided more active sites on their surface and the strong interaction with Ag nanoparticles. The CSM-dots can specifically bind Ag+, accompanied by a remarkable fluorescence quenching response. This “turn-off” fluorescence behavior was used for Ag+ determination in a linear range of 5–290 μM with the detection limit as low as 500 nM. Furthermore, findings showed that this sensing nano-platform was successfully used for Ag+ determination in real samples and intracellular imaging, showing great potential in biological and environmental monitoring applications.

A novel signal-on fluorometric sensor based on metal ion-mediated carbon dots for formaldehyde determination and lysosome-targeted bioimaging

“…S1d, ESI †) reveals the presence of S 2p 1/2 (165.24 eV) and S 2p 3/2 (164.57 eV). 28 The above analysis further confirms that the NSCDs were functionalized with a variety of functional groups, including -COOH, -OH, -SO 3 H and -NH 2 . 30 Meanwhile, the optical properties of NSCDs were investigated by the UV-visible spectrum and the FL spectrum.…”

“…13 This result is ascribed to single benzene units and their weak interaction in the whole amorphous structure of lignin. 28 FT-IR spectra of lignin, urea and NSCDs (Fig. 1c) show that a broad absorption peak centered at 3418 cm À1 in the NSCDs is attributed to the O-H/N-H stretching vibration, and the peak at 1236 cm À1 is assigned to the stretching vibration of the SQO bonds of sulfonic acid groups.…”

One-step facile preparation of carbon dots with high fluorescence quantum yield and application in rapid latent fingerprint detection

“…3a), which again indicated the presence of a disordered graphitic structure and formation of carbon dots. 24–27…”

“…7b–e), the C 1s band was deconvoluted into four peaks corresponding to the sp 2 - and sp 3 -hybridized carbons of C–C/CC (284.6 eV), C–O/C–S/C–N (285.1 eV), CO (288.5 eV), and CO/CN (288.1 eV) moieties. 27,34,35 The N 1s band was deconvoluted into three peaks at 398.9, 399.5, and 400.0 eV, which represented CN, C–N–C, and N–H moieties, 36 respectively, indicating that N atoms were present in the GCDs. The O 1s band contained four peaks at 530.8, 531.5, 532.6 and 535.5 eV, representing C–O, OS/CO, CO/C–O and C–OH/C–O–C.…”

“…3a), which again indicated the presence of a disordered graphitic structure and formation of carbon dots. [24][25][26][27] To determine the optical properties of GCDs and GCD-starch powder, the UV-Vis absorption spectra of starch, GCDs, and GCD-starch powder were compared, as shown in Fig. 3b.…”