Wavelength-Dependent Surface Plasmon Coupling Electrochemiluminescence Biosensor Based on Sulfur-Doped Carbon Nitride Quantum Dots for K-RAS Gene Detection

Abstract

Although graphite phase carbon nitride quantum dots (GCN QDs) showed some advantages in the electrochemiluminescence (ECL) analytical research, the low ECL efficiency limited the potential sensing application. Herein, we synthesized sulfur-doped graphite phase carbon nitride quantum dots (S-GCN QDs) to fabricate a sandwich sensor based on amplified surface plasmon coupling ECL (SPC-ECL) mode. Sulfur doping can change the surface states of QDs effectively and produced new element vacancy. As a result, the ECL efficiency of S-GCN QDs was 2.5× over GCN QDs. Furthermore, compared with the big gap between the ECL peak of GCN QDs (620 nm) and the absorption peak of Au NPs, the doped sulfur elements in S-GCN QDs generated new ECL emission peaks at 555 nm, which was closed to the absorption peak of Au NPs at 530 nm. Due to the wavelength-dependent surface plasmon coupling effect, the ECL peak of S-GCN QDs at 555 nm had greater amplitude of enhancement in the sensing system. The proposed biosensor can quantify the K-RAS gene from 50 fM to 1 nM with a limit of detection (LOD) of 16 fM. We were the first to provide insight into the role of wavelength-dependent surface plasmon coupling in enhancing the sensitivity of ECL biosensor.

Fabrication of recyclable reduced graphene oxide/graphitic carbon nitride quantum dot aerogel hybrids with enhanced photocatalytic activity

“…3c ). 44 The functional groups in the aerogel hybrids were clearly mainly derived from rGO and CNQDs, suggesting that the CNQDs were incorporated well with rGO. The O 1s spectrum showed two binding energies at 532.0 and 531.1 eV, which were assigned to C O and C–O, respectively ( Fig.…”

Fabrication of g-C3N4/Bi2WO6 as a direct Z-scheme excellent photocatalyst

“…In Fig. 2b, the highresolution spectra of C 1s could be fitted by three peaks at 288.5, 285.4, and 284.4 eV, which corresponded to COOH, CQN-C, and C-C/CQC, 36 respectively. The existence of CQN-C in the aromatic ring in both samples suggested that the basic substructure of the CNQDs had the same heptazine heterocyclic ring backbone as the CNNSs.…”

Element-doped graphitic carbon nitride: confirmation of doped elements and applications

“…Therefore, a novel sensor for detecting folic acid, whose detection limit is 16 nM with a linear range of 0.05-200 μM, was successfully prepared. The sensing of other organics, such as L-cysteine, 206 and K-RAS Gene, 169 can be achieved via ECL measurements. Element-doped g-CN-based sensor systems are also useful to detect heavy metal ions, which are ubiquitous in environmental pollutants.…”