Building a Three-Dimensional Nano–Bio Interface for Aptasensing: An Analytical Methodology Based on Steric Hindrance Initiated Signal Amplification Effect

Abstract

The development of novel detection methodologies in electrochemiluminescence (ECL) aptasensor fields with simplicity and ultrasensitivity is essential for constructing biosensing architectures. Herein, a facile, specific, and sensitive methodology was developed unprecedentedly for quantitative detection of microcystin-LR (MC-LR) based on three-dimensional boron and nitrogen codoped graphene hydrogels (BN-GHs) assisted steric hindrance amplifying effect between the aptamer and target analytes. The recognition reaction was monitored by quartz crystal microbalance (QCM) to validate the possible steric hindrance effect. First, the BN-GHs were synthesized via self-assembled hydrothermal method and then applied as the Ru(bpy) immobilization platform for further loading the biomolecule aptamers due to their nanoporous structure and large specific surface area. Interestingly, we discovered for the first time that, without the aid of conventional double-stranded DNA configuration, such three-dimensional nanomaterials can directly amplify the steric hindrance effect between the aptamer and target analytes to a detectable level, and this facile methodology could be for an exquisite assay. With the MC-LR as a model, this novel ECL biosensor showed a high sensitivity and a wide linear range. This strategy supplies a simple and versatile platform for specific and sensitive determination of a wide range of aptamer-related targets, implying that three-dimensional nanomaterials would play a crucial role in engineering and developing novel detection methodologies for ECL aptasensing fields.

Determination of microcystin-LR, employing aptasensors

“…This sensing system does not require high price labelling and complicated probe immobilization stage. After incubation of aptasensor with 5 pM, an RSD of 5.3% was obtained (n=12), suggesting a good repeatability (Du et al 2016c).…”

“…Three-dimensional graphene hydrogels (3D GHs), as a new generation of ultralight and porous carbon-based materials have attracted extensive attention. 3D GHs not only represent high surface to volume ratio, but also provide special sites for ECL luminophore molecules assembly (Du et al 2016c).…”

“…Recently, an ECL aptasensor was designed with an LOD of 0.03 pM (Du et al 2016c). In this case, boron and nitrogen co-doped graphene hydrogels (BN-GHs) were used to amplify steric hindrance between MC-LR and its specific aptamer.…”

Aptamers for Diagnostics with Applications for Infectious Diseases

“…This assay was enabled by highly specific aptamers conjugated with photoluminescent carbon dots as the fluorescent probe and graphene oxide as the quencher, and it allowed detection of as low as 9 CFU mL −1 P. aeruginosa [39]. Electrochemiluminescence is another output option for aptasensors [40].…”

Aptamer-Based Biosensors to Detect Aquatic Phycotoxins and Cyanotoxins

“…They can be amperometric, potentiometric, impedimetric and ion-change or field effect. The working electrode(s) are usually made of gold [ 28 , 29 , 30 , 31 ], indium tin oxide [ 32 ], or carbon-based compounds [ 23 , 33 , 34 , 35 ], screen-printed or with a self-assembled layer on top [ 36 , 37 , 38 ], further covered by the bioreceptor. Amperometric sensors measure the production of a current when a potential is applied between two electrodes.…”