An electrochemical aptasensor for detection of prostate‐specific antigen using reduced graphene gold nanocomposite and Cu/carbon quantum dots

Abstract

We report a label-free electrochemical aptamer-based biosensor for the detection of human prostate-specific antigen (PSA). The thiolate DNA aptamer against PSA was conjugated to the reduced graphene oxide/Au (RGO-Au) nanocomposite through the self-assembly of Au-S groups. Owing to the large volume to surface ratio, the RGO-Au nanocomposite provides a large surface for aptamer loading. The RGO-Au/aptamer was combined with a Nafion polymer and immobilized on a glassy carbon electrode. The interaction of aptamer with PSA was studied by cyclic voltammetry, square wave voltammetry, and electrochemical impedance spectroscopy. The detection of limit for prepared electrode was obtained about 50 pg/mL at the potential of 0.4 V in potassium hexacyanoferrate [K 4 Fe(CN) 6 ] medium. To decrease the limit of detection (LOD) and applied potential of the prepared nanoprobe Cu/carbon quantum dots (CuCQD) is introduced as a new redox. The results show that this new electrochemical medium provides better conditions for the detection of PSA. LOD of a nanoprobe in CuCQD media was obtained as 40 pg/mL at the potential of −0.2 V. Under optimal conditions, the aptasensor exhibits a linear response to PSA with a LOD as small as 3 pg/mL. The present aptasensor is highly selective and sensitive and shows satisfactory stability and repeatability.

Nanoscale metallic‐organic frameworks as an advanced tool for medical applications: Challenges and recent progress

“…[ 137 ] Also, making sensors to detect cancer biomarkers is another way to use them for cancer diagnosis. [ 138,139 ]…”

“…[ 7 ] Nanostructures show superior features including large surface area, high reactivity, tailorable physical properties, good stability, and exceptional optical properties that facilitate their use in bioimaging and biosensing. [ 8–10 ]…”

A novel pH‐responsive nanoniosomal emulsion for sustained release of curcumin from a chitosan‐based nanocarrier: Emphasis on the concurrent improvement of loading, sustained release, and apoptosis induction

“…40,41 The change in the pH of cancer cells during their proliferation is one of the main reasons for this popularity. 42,43 This reduction in pH, known as the Warburg effect, is a hallmark in cancer and has led to applying pH-sensitive drug delivery platforms like hydrogels for the controlled delivery of anti-cancer therapeutics. 44,45 As mentioned before, a hydrogel of CS-Aga was prepared in this study.…”

“…Anti‐cancer drug delivery platforms that respond to pH are among the most popular stimuli‐responsive drug delivery options 40,41 . The change in the pH of cancer cells during their proliferation is one of the main reasons for this popularity 42,43 . This reduction in pH, known as the Warburg effect, is a hallmark in cancer and has led to applying pH‐sensitive drug delivery platforms like hydrogels for the controlled delivery of anti‐cancer therapeutics 44,45 …”

Fabrication of Au/Fe3O4/RGO based aptasensor for measurement of miRNA‐128, a biomarker for acute lymphoblastic leukemia (ALL)

“…Gold nanoparticles and their composites also are very suitable for miniaturized sensing platforms, especially electrochemical biosensors, because of their wide electrochemical potential range, simple preparation, easy fabrication process, and high catalytic activity [63][64][65][66]. In nanohybrids, all advantages of the comprising species can be magnified due to the synergic interaction between them [67]. For instance, nanohybrids can be very efficient in immobilizing the bioreceptors and adsorbing the desired biomolecules at the same time, which makes the fabricated biosensor very selective [68,69].…”