Guozhen Liu’s research while affiliated with The University of Hong Kong and other places

The Phi29 DNA polymerase is renowned for its processivity in synthesizing single-stranded DNA amplicons by rolling around a circularized DNA template. However, DNA synthesis rolling circle amplification (RCA) is significantly hindered by the secondary structure in the circular template. To overcome this limitation, an engineered circular template without secondary structure could be utilized to improve the sensitivity of RCA-based assays without increasing its complexity. We herein proposed an entropy-driven special RCA technology for the detection of HPV16 E7 gene at room temperature. The strategy is composed of a molecular beacon containing a loop region for nucleic acid target recognition and a stem region to initiate RCA. With the target analyte, the stem region of the molecular beacon will be exposed and then hybridized with a special circular template to initiate the DNA amplification. We tested different designs of the molecular beacon sequence and optimized the assay’s working conditions. The assay achieved a sensitivity of 1 pM in 40 min at room temperature. The sensitivity of this assay, at 1 pm, is about a hundred-fold greater than that of conventional linear RCA performed in solution. Our proposed sensor can be easily reprogrammed for detecting various nucleic acid markers by altering the molecular beacon’s loop. Its simplicity, rapid assay time, and low cost make it superior to RCA sensors that utilize similar strategies.

The liver is an immune organ, especially an immune tolerance organ. The critical shortage of donor organs and disease models for the treatment of end‐stage liver failure underscores the urgent need for the generation of liver organoids from human induced pluripotent stem cells (iPSCs). Notably, significant advancements have been made in the study of liver organoids over the past decade. The construction of liver organoids has transitioned from single cell type to multicellular models, and from two‐dimensional to three‐dimensional cultures. Here we provide the progress surrounding the different liver organoids culture techniques from 3D printing to organ‐on‐chip, as well as focuses on the present and future applications of liver organoids, and then to present challenges and perspectives ahead for further advancement.

Saliva contains a diverse array of biomarkers indicative of various diseases. Saliva testing has been a major advancement towards non-invasive point-of-care diagnosis with clinical significance. However, there are challenges associated with salivary diagnosis from sample treatment and standardization. This review highlights the biomarkers in saliva and their role in identifying relevant diseases. It provides an overview and discussion about the current practice of saliva collection and processing, and advancements in saliva detection systems from in vitro methods to wearable oral devices. The review also addresses challenges in saliva diagnostics and proposes solutions, aiming to offer a comprehensive understanding and practical guidance for improving saliva-based detection in clinical diagnosis. Saliva diagnosis provides a rapid, effective, and safe alternative to traditional blood and urine tests for screening large populations and enhancing infectious disease diagnosis and surveillance. It meets the needs of various fields such as disease management, drug screening, and personalized healthcare with advances in saliva detection systems offering high sensitivity, fast response times, portability, and automation. Standardization of saliva collection, treatment, biomarker discovery, and detection between different laboratories needs to be implemented to obtain reliable salivary diagnosis in clinical practice.

Both carboxyl and amino groups have binding affinity for the EGaIn surface with a probability of 7 : 3, forming an effective sensing interface for detection of IL-6.

Extracellular vesicles (EVs) carry disease‐specific molecular profiles, demonstrating massive potential in biomarker discovery. In this study, we developed an integrated biochip platform, termed EVID‐biochip (EVs identification and detection biochip), which integrates in situ electrochemical protein detection with on‐chip antifouling‐immunomagnetic beads modified with CD81 antibodies and zwitterion molecules, enabling efficient isolation and detection of neuronal EVs. The capability of the EVID‐biochip to isolate common EVs and detect neuronal EVs associated with Parkinson's disease in human serum is successfully demonstrated, using the transmembrane protein L1‐cell adhesion molecule (L1CAM) as a target biomarker. The EVID‐biochip exhibited high efficiency and specificity for the detection of L1CAM with a sensitivity of 1 pg/mL. Based on the validation of 76 human serum samples, for the first time, this study discovered that the level of L1CAM/neuronal EV particles in serum could serve as a reliable indicator to distinguish Parkinson's disease from control groups with AUC = 0.973. EVID‐biochip represents a reliable and rapid liquid biopsy platform for the analysis of complex biofluids offering EVs isolation and detection in a single chip, requiring a small sample volume (300 µL) and an assay time of 1.5 h. This approach has the potential to advance the diagnosis and biomarker discovery of various neurological disorders and other diseases.