Hybridization chain reaction and gold nanoparticles dual signal amplification for sensitive glucose detection

Design Strategies of Gold Nanoparticles‐Based Biosensors Coupled with Hybridization Chain Reaction or Catalytic Hairpin Assembly

“…[41] In another electrochemical study, Li et al used a turn-off approach whereby molecular beacons that interact with glucose detection probes were immobilised onto an electrode. [44] When HCR was triggered with two Fc-labelled hairpins, the group further strengthened the electrochemical signal by adding positively-charged AuNPs that electrostatically adsorbed onto the elongated HCR product. However, in the presence of glucose, glucose oxidase and Fe 2 + , the glucose detection probes were cleaved due to production of hydrogen peroxide, hence HCR was inhibited.…”

“…However, in the presence of glucose, glucose oxidase and Fe 2 + , the glucose detection probes were cleaved due to production of hydrogen peroxide, hence HCR was inhibited. [44] Instead of immobilizing oligonucleotide probes on electrode, Yang and co-workers utilized antibodies to capture carbohydrate antigen 125 (CA125), an ovarian cancer biomarker. [45] The target CA125 was sandwiched by aptamerprimer sequences, which further connected to H1-conjugated AuNPs.…”

“…H. pylori DNA 0.68 aM 0.01-0.5 fM ; 1-100 fM DNA-functionalised /13 nm HCR -100 min Total -8 hr [40] Electrochemical CA125 50 μU/mL 100 μU/mL-10 U/ mL DNA-functionalised /13 nm HCR -2 hr [45] Electrochemical Glucose 21 pM 50 pM-2 nM CTAB-coated/4 nm HCR -60 min Mix with AuNPs -30 min [44] Electrochemical miRNA-21 0.12 fM 1 fM- ICP-MS DNA [b] 3 fM 5 fM-10 pM DNA-functionalised AuNPs/32 nm HCR -1 hr Incubation of AuNPs -2 hr [58] [a]…”

Electrochemical Biosensors Employing Hybridization Chain Reaction: From Structural Design to Applications

“…As an indispensable part of carbohydrate metabolism, glucose can directly control brain activity, but a high concentration of it will cause diabetes. [51,72] Conventionally, it does not require any amplification for glucose detection in whole blood as the relevant clinic concentrations are in the millimolar range. Nevertheless, when it comes to glucose detection in other biofluids such as sweat or urine, it is of great interest to employ HCR [73] amplifications into electrochemical biosensors as the concentration range is on the micromolar scale or even lower.…”

“…The difference between these two signals reflects the concentrations of target analytes. [51] The final strategy, also known as "competition mode," relies on the binding competition of the target and ligand with its auxiliary probe (Figure 7). Specifically, this auxiliary probe first binds to a ligand, which interacts with the target and can be released into its unbound state.…”