Compact and Versatile Nickel-Nitrilotriacetate-Modified Quantum Dots for Protein Imaging and Förster Resonance Energy Transfer Based Assay

Abstract

The generation of compact quantum dots (QDs) probes is of critical importance for visualizing molecular interaction occurring in biological context, particularly when using the Förster resonance energy transfer (FRET) approach. This Article reports novel water-soluble compact CdSe/ZnS QDs prepared by ligand exchange reaction using thiolated nitrilotriacetate (NTA). The resulting NTA-QDs revealed higher stability and remarkable conjugation efficiency compared to the other QDs prepared with different ligands by using the ligand exchange method. The Ni-NTA group is a well-known binding moiety for the detection and purification of oligohistidine-tagged recombinant proteins. We demonstrated that NiNTA-QDs prepared by Ni(2+) complexation exhibited highly specific binding ability toward 6-histidine (His)-tagged peptides present in various experimental conditions (buffer solution, agarose beads, and HEK cells). Importantly, the compact NiNTA-QDs serve as an efficient FRET donor. These results suggest that the stable and highly selective multifunctional NTA-QDs can be useful for labeling and tracking molecular interactions within biological context.

Single Cell Optical Imaging and Spectroscopy

“…Many strategies exist for generating surface functionalized QDs for cellular measurements. 277,385-386 …”

Quantum dot photosensitizers. Interactions with transition metal centers

“…However, a remaining major challenge to those who wish to utilize QDs as photosensitizer chromophores, ourselves included, is to develop reproducible protocols to prepare and characterize well-defined surfaces derivatized to meet the desired goals. With the resulting accessibility and versatility of such systems, QDs have found use in applications such as solar cells, [46][47][48][49][50][51][52][53][54][55][56][57] light emitting diodes (LEDs), 58-61 biological imaging and labeling [62][63][64][65][66][67] and sensing. [68][69][70][71][72][73][74][75][76][77][78][79][80][81][82][83] Energy transfer and charge transfer pathways Before discussing the details of quantum dot energy and charge (electron) transfer pathways, it is of value to review briefly the expectations one has based on molecular photophysics.…”

Manganese modified CdTe/CdS quantum dots as an immunoassay biosensor for the detection of Golgi protein-73

“…So, given that its biochemical function is unknown at present, it 50 is a potential prognostic biomarker for monitoring liver cancer and could improve the 51 differential diagnosis of hepatic diseases when combined with AFP and ultrasound 52 examination [10]. Many analytical methods have been developed for GP73 detection, 53 such as double antibody sandwich ELISA [11,12], lectin capture strategies [13] and 54 western blotting [14] whereas only double antibody sandwich ELISA is applied to the 55 clinical diagnosis for GP73 protein. Meantime, these methods suffer from the 56 emission spectra and good biocompatibility [16,17].…”