Ultra-sensitive DNA sensing of a prostate-specific antigen based on 2D nanosheets in live cells

Abstract

Herein, we report ultra-sensitive sensing of a prostate-specific antigen (PSA), which is used as a biomarker to detect prostate cancer, using a molybdenum series (MoO, MoS, and MoSe) of two-dimensional nanosheets (2D NSs). Moreover, the design of a 2D NS-based PSA aptamer sensor system was demonstrated based on a fluorescence turn-on mechanism in the presence of a target. The 2D NSs acted as an excellent sensing platform in which the PSA aptamer was adsorbed on the NSs and subsequent energy transfer between them led to fluorescence quenching of the aptamer. The detection limit of PSA was achieved to be 13 pM for MoO NSs, whereas the MoS and MoSe systems exhibited a detection limit of 72 and 157 pM, respectively. To the best of our knowledge, this is the first report on the ultra-sensitive detection of a 2D NS-based aptamer sensor. The in vitro bioimaging measurements were performed using confocal fluorescence microscopy. Herein, PSA detection was successfully demonstrated in human embryonic kidney 293T (HEK) live cells. Moreover, the MoO, MoS, and MoSe NSs exhibit excellent biocompatibility and low toxicity; thus, these 2D NSs can be used as a promising sensor platform to detect prostate cancer.

2D metal oxide nanoflakes for sensing applications: Review and perspective

“…Fluorescent sensors require light-absorbing materials such as MoO 3 and MnO 2 [38,67,83,84] to quench the fluorescence of the signaling species. Most 2D transition metal oxides show intensive light absorption due to strong d-d transitions [109].…”

“…Most 2D transition metal oxides show intensive light absorption due to strong d-d transitions [109]. Metal oxides can be beneficial for fluorescent sensing as compared to metal sulfides and selenides because the oxygen atoms yield stronger electrostatic interactions with the signaling species, which causes closer proximity and more efficient quenching [84]. An advantage of atomically thin MnO 2 nanoflakes is that they are also strongly oxidative towards organic compounds and this feature can be employed in combination with their light absorption [67,85].…”

“…In contrast, very high selectivities can be reached for nanoflakes decorated with signaling moieties that interact with the target molecules via e.g. DNA or peptide recognition [38,83,84]. Adsorption-based sensing of solutes often only involves turn-on sensing; once the target molecules are bound by the sensing platform, they do not detach spontaneously anymore.…”

“…Upon interaction of the signaling species with the target molecule, e.g. via DNA hybridization, the signaling species (partially) desorbs and the dye label escapes from the quenching influence of the metal oxide nanoflakes, thus retaining its fluorescence [38,83,84]. Alternatively, the fluorescent signaling species can be released via consumption of the metal oxide nanosheets in oxidation reactions with the target species [67,85].…”

Metal Nanoparticles Anchored on Rhenium Disulfide Nanosheets as Catalysts for the Reduction of Aromatic Nitro Compounds

“…Beyond graphene, transition metal dichalcogenides (TMD) such as MoS 2 , WS 2 , ReS 2 , MoSe 2 , etc. are newly emerging materials which are widely employed in various research fields, due to their unique physical and chemical properties . The 2D TMD materials were generally prepared by exfoliation of their bulk material in which the defect sites appear as caused by the vacancies of chalcogen on the surface .…”