3-Mercapto propionic acid self-assembled on gold nano-particles applied for modification of screen-printed electrode as a new digoxin electrochemical aptasensor using graphene oxide-based signal-on strategy

Abstract

In this study a new electrochemical aptasensor has been represented for digoxin determination using signal-on strategy to improve limit of detection. To construct the sensor, gold screen printed electrode (GSPE) was modified with electrodeposited gold nanoparticles (GNPs) followed by self-assembling a layer of 3-mercaptopropionic acid (MPA) on the GNPs. Aminolabeled digoxin specific aptamer was covalently attached to the surface via carbodiimide bond formation. Graphene oxide (GO) was accumulated on the electrode surface through interaction with aromatic nucleobases in aptamer structure and the monitored reduction signal of potassium ferriciyanide as a redox probe was decreased. In the presence of digoxin, the immobilized GO left the surface and the current was increased and recorded as analytical signal. The proposed sensor was delivered a linear dynamic response over the range of 0.1 pM to 1.0 µM with a detection limit of 0.050 pM. The ability of the aptasensor in real sample analysis was successfully evaluated by determination of digoxin in human blood plasma samples with no serious matrix interferences.

Characterization of Recombinant His-Tag Protein Immobilized onto Functionalized Gold Nanoparticles

“…SAMs of thiols on nanoparticles have been employed as a platform for the construction of biomaterials. The nanoscale properties, such as high conductivity and biocompatibility, coupled with the high selectivity offered by the biomolecules are ideal for biomaterial development [13]. The most popular nanomaterial to conjugate with thiols are gold nanoparticles (AuNPs) due to their extraordinary optical, electronic, and molecular recognition properties [14,15].…”

Electrochemically driven optical and SERS immunosensor for the detection of a therapeutic cardiac drug

“…Nikfarjam et al , 2017, reported LOD of 2 ng mL −1 , while Ahmadi et al reported LOD of 0.05 ng mL −1 using electrochemical biosensor. While LOD achieved using various optical and electrochemical aptasensors were 0.01 mg L −1 , 37 0.05 pM, 38 1.85 ng mL −1 (ref. 39 ) and 1 pM.…”

“…31 On the other hand Au-NPs changes the optical behavior of organic molecules on conjugation 26,32 by multiplexing through SERS tag as its spectra give information of a whole range of molecules present in the sample. 30,33 Recent studies have also reported digoxin detection through electrochemical method using Au coated magnetic nanoparticles, 31,[34][35][36] optical and electrochemical aptasensors [37][38][39][40] immunochromatographic strip using colloidal Au-NPs, uoroimmunoassay, 41 bioluminescent, 26 amperometric, 42 low surface plasmon resonance of AuNPs, 43 and impedance spectroscopy. 44 However, no extensive or a detailed study is available for digoxin optical and electrochemical detection through QDs so far.…”

Quantitative Detection of Digoxin in Plasma Using Small‐Molecule Immunoassay in a Recyclable Gravity‐Driven Microfluidic Chip

“…It should be noted that the simulations associated with the optimization of the amount of beads, kinetics, and digoxin detection here are quite consistent with the experimental results (see Section S4, Supporting Information). Also, refer Table S3 in the Supporting Information for detailed comparison between the current method and last 5 year literatures as well as associated commercial kits …”