An Emerging Toolkit of Ho Sensitized Lanthanide Nanocrystals with NIR-II Excitation and Emission for Bioimaging.

Optical imaging in the second near-infrared window (NIR-II, 1000-1700 nm) holds great promise for biomedical detection due to reduced tissue scattering and autofluorescence. However, the rational design of NIR-II probes with superior excitation wavelengths to balance the effects of tissue scattering and water absorption remains a great challenge. To address this issue, here we developed a series of Ho-sensitized lanthanide (Ln) nanocrystals (NaYF: Ho, Ln@NaYF) excited at 1143 nm, featuring tunable emissions ranging from 1000 to 2200 nm for bioimaging.

Rapid and Accurate Identification of Cell Phenotypes of Different Drug Mechanisms by Using Single-Cell Fluorescence Images Via Deep Learning.

Identification of a drug mechanism is vital for drug development. However, it often resorts to the expensive and cumbersome omics methods along with complex data analysis. Herein, we developed a methodology to analyze organelle staining images of single cells using a deep learning algorithm (TL-ResNet50) for rapid and accurate identification of different drug mechanisms.

Intraparticle and Interparticle Transferable DNA Walker Supported by DNA Micelles for Rapid Detection of MicroRNA.

Synthetic DNA walkers are artificially designed DNA self-assemblies with the capability of performing quasi-mechanical movement at the micro/nanoscale and have shown extensive promise in biosensing, intracellular imaging, and drug delivery. However, DNA walkers are usually constructed by covalently or coordinately binding DNA strands specifically to hard surfaces, thereby greatly limiting their movement efficiency. Herein, we report an intraparticle and interparticle transferable DNA walker (dynamic micelle-supported DNA walker, DM-walker) constructed by immobilizing walking tracks and walking arms onto the corona of DNA micelles according to the principle of Watson-Crick base pairing.

A simple enzyme-assisted cascade amplification strategy for ultrasensitive and label-free detection of DNA.

A simple fluorescence biosensor is developed based on the enzyme-assisted cascade amplification strategy. The amplification system consists of a hairpin-structure DNA (H-DNA) and exonuclease III. The target DNA can hybridize with the H-DNA and initiate exonuclease III-assisted target recycling amplification to generate abundant G-rich DNA (G-DNA).

DNA-fueled target recycling-induced two-leg DNA walker for amplified electrochemical detection of nucleic acid.

Taking advantage of the homogeneous and heterogeneous electrochemical biosensors, a simple, sensitive, and selective electrochemical biosensor is constructed by combining entropy-driven amplification (EDA) with DNA walker. This electrochemical biosensor realizes the biorecognition and EDA operation in homogeneous solution, which is beneficial to improve the recognition and amplification efficiency. A two-leg DNA walker generated by EDA can walk on the surface of gold electrode for cleaving the immobilized substrate DNA and releasing the electroactive labels, giving rise to a significant decrease of the electrochemical signal.

Autonomous DNA nanomachine based on cascade amplification of strand displacement and DNA walker for detection of multiple DNAs.

DNA can be modified to function as a scaffold for the construction of a DNA nanomachine, which can then be used in analytical applications if the DNA nanomachine can be triggered by the presence of a diagnostic DNA or some other analyte. We herein propose a novel and powerful DNA nanomachine that can detect DNA via combining the tandem strand displacement reactions and a DNA walker. Three different DNA sensing platforms are described, where the whole DNA machine was constructed on a gold electrode (GE).

A novel electrochemical biosensor based on polyadenine modified aptamer for label-free and ultrasensitive detection of human breast cancer cells.

Simple, rapid, sensitive, and specific detection of cancer cells plays a pivotal role in the diagnosis and prognosis of cancer. A sandwich electrochemical biosensor was developed based on polyadenine (polydA)-aptamer modified gold electrode (GE) and polydA-aptamer functionalized gold nanoparticles/graphene oxide (AuNPs/GO) hybrid for the label-free and selective detection of breast cancer cells (MCF-7) via a differential pulse voltammetry (DPV) technique. Due to the intrinsic affinity between multiple consecutive adenines of polydA sequences and gold, polydA modified aptamer instead of thiol terminated aptamer was immobilized on the surface of GE and AuNPs/GO.