A universal CRISPR/Cas12a-powered intelligent point-of-care testing platform for multiple small molecules in the healthcare, environment, and food.

Growing studies focusing on nuclear acid detection via the emerging CRISPR technique demonstrate its promising application. However, limited works solve the identification of non-nucleic acid targets, especially multiple small molecules. To address challenges for point-of-care testing (POCT) in complex matrices for healthcare, environment, and food safety, we developed CRISPR Cas12a-powered highly sensitive, high throughput, intelligent POCT (iPOCT) for multiple small molecules based on a smartphone-controlled reader. As a proof of concept, aflatoxin B1 (AFB1), benzo[a]pyrene (BaP), and capsaicin (CAP) were chosen as multiple targets. First, three antigens were preloaded in independent microwells. Then, the antibody/antigen-induced fluorescent signals were consecutively transferred from the biotin-streptavidin to CRISPR/Cas12a system. Third, the fluorescent signals were recorded by a smartphone-controlled handheld dark-box readout. Under optimization, detection limits in AFB1, BaP, and CAP were 0.00257, 4.971, and 794.6 fg/mL with wide linear ranges up to four orders of magnitude. Using urine, water, soybean oil, wheat, and peanuts as the complex matrix, we recorded high selectivity, considerable recovery, repeatability, and high consistency comparison to HPLC-MS/MS methods. This work promises a practical intelligent POCT platform for multiple targets in lipid-soluble and water-soluble matrices and could be extensively applied for healthcare, environment, and food safety.

The isolation, structural features and biological activities of polysaccharide from Ligusticum chuanxiong: A review.

Ligusticum chuanxiong, the dried rhizome of Ligusticum chuanxiong Hort, has been widely applied in traditional Chinese medicine for treating plague, and it has appeared frequently in the prescriptions against COVID-19 lately. Ligusticum chuanxiong polysaccharide (LCPs) is one of the effective substances, which has various activities, such as, anti-oxidation, promoting immunity, anti-tumor, and anti-bacteria. The purified fractions of LCPs are considered to be pectic polysaccharides, which are mainly composed of GalA, Gal, Ara and Rha, and are generally linked by α-1,4-d-GalpA, α-1,2-l-Rhap, α-1,5-l-Araf, ß-1,3-d-Galp and ß-1,4-d-Galp, etc. The pectic polysaccharide shows an anti-infective inflammatory activity, which is related to antiviral infection of Ligusticum chuanxiong. In this article, the isolation, purification, structural features, and biological activities of LCPs in recent years are reviewed, and the potential of LCPs against viral infection as well as questions that need future research are discussed.