Boron Carbon Nitride Nanosheets-Ru Nanocomposite Self-Enhancement Electrochemiluminescence Emitter with a Three-Dimensional DNA Network Structure as a Signal Amplifier for Ultrasensitive Detection of TK1 mRNA

Abstract

In this study, a neoteric self-enhanced nanocomposite boron carbon nitride nanosheets (BCN NSs)-Ru obtained by chemical crosslinking between boron carbon nitride nanosheets (BCN NSs) and tris (4,4′-dicarboxylicacid-2,2′-bipyridyl) ruthenium(II) dichloride (Ru(dcbpy) 3 Cl 2 ) was used as an emitter to build an electrochemiluminescence (ECL) biosensor for ultrasensitive detection of the cancer marker human thymidine kinase 1 (TK1) mRNA. Importantly, the self-enhanced BCN NSs-Ru could exhibit strong ECL emission because boron radicals and amine groups derived from BCN NSs could significantly enhance the ECL response of Ru(dcbpy) 3 Cl 2 , which avoided the defects of the long electron transfer path and large energy loss between the emitter and coreactant in the traditional coreaction ECL system. Impressively, in the presence of target TK1 mRNA, three-dimensional DNA network structure-labeled numerous ferrocene probes could be assembled to quickly quench the ECL signal of BCN NSs-Ru, resulting in improved biosensor sensitivity. The obtained "on−off" biosensor showed excellent stability and high sensitivity with a detection limit of 32.3 aM. In general, the developed strategy provided a new biosensing way for ultrasensitive detection of biomolecules in early disease diagnosis.

Aggregation-Induced Electrochemiluminescence of Copper Nanoclusters by Regulating Valence State Ratio of Cu(I)/Cu(0) for Ultrasensitive Detection of MicroRNA

“…Next, capture DNA which was treated by tris­(2-carboxyethyl)-phosphine (TCEP) could be modified onto the above electrode surface via Au–S bonds overnight at 4 °C. Then, 10 μL of a 1 mM hexanethiol solution (HT) was dropped on the modified GCE at RT for 40 min for closure of the nonspecific adsorption sites . Then, the obtained electrode was treated in 10 μL of 3 μM Fc-DNA at 37 °C for 2 h to let Fc-DNA hybridize with the capture DNA.…”

“…Then, 10 μL of a 1 mM hexanethiol solution (HT) was dropped on the modified GCE at RT for 40 min for closure of the nonspecific adsorption sites. 12 Then, the obtained electrode was treated in 10 μL of 3 μM Fc-DNA at 37 °C for 2 h to let Fc-DNA hybridize with the capture DNA. In the end, the acquired electrode was incubated with 10 μL of output DNA to replace the Fc-DNA.…”

Electrochemiluminescence from Single Molecule to Imaging

“…In addition, the efficiency of ECL is also affected by many factors, such as electrode material, co-reactant, imaging buffer, electrolyte, and so on. To enhance the detection and imaging contrast of ECL, the following improvements are under development: the common strategy for positive labeling detection is to synthesize brighter dyes and the enrichment and cascade amplification of luminescent probes or co-reactants such as ECL systems based on quantum dots ,− (see Figure C), porous materials, − single-atom catalyst, − carbon-based materials, − and the rational design of co-reactants. − In addition to the designing of novel ECL probes and co-reactant, the electrode applied in the ECL reaction is an important part of the ECL imaging system, which can also be improved . As a new type of semiconductor electrode, the boron-doped diamond electrode (BDDE) has a good redox window in aqueous solution, which can avoid the side reaction of water electrolysis on ECL .…”

Directionally In Situ Self-Assembled Iridium(III)-Polyimine Complex-Encapsulated Metal–Organic Framework Two-Dimensional Nanosheet Electrode To Boost Electrochemiluminescence Sensing

“…3,4 Thus, the ECL technique opens up a new avenue to aqueous sensing for water-insoluble metal complexes through immobilizing them on electrode surfaces. 5,6 In addition, the ECL technique enjoys low background, high sensitivity, and strong anti-interference ability due to the complete difference in energy forms of input and export. 7−10 However, investigations of metal complexes on ECL in water solution are scarcely reported, attributable to most metal complexes being subject to the aggregation-caused quenching (ACQ) effect and easily declining intensity; 11,12 preparing watersoluble metal complexes like Ru(bpy) 2 3+ is punitive.…”

“…Metal complex light-emitting probes play an important role in fields of life, food, and environmental sciences. , Unfortunately, their applications in water solution are constrained because of organic solvent solubility. Electrochemiluminescence (ECL) inflicts voltage on electrodes to active emitters for yielding intermediates that undergo electron gain and loss to form excited-state luminophores, showing bright emission. , Thus, the ECL technique opens up a new avenue to aqueous sensing for water-insoluble metal complexes through immobilizing them on electrode surfaces. , In addition, the ECL technique enjoys low background, high sensitivity, and strong anti-interference ability due to the complete difference in energy forms of input and export. − However, investigations of metal complexes on ECL in water solution are scarcely reported, attributable to most metal complexes being subject to the aggregation-caused quenching (ACQ) effect and easily declining intensity; , preparing water-soluble metal complexes like Ru­(bpy) 2 3+ is punitive. , …”