A low-voltage alternant direct current electroporation chip for ultrafast releasing the genome DNA of Helicobacter pylori bacterium.

Nucleic acid detection, as an important molecular diagnostic method, is widely used in bacterial identification, disease diagnosis. For detecting the nucleic acid of bacteria, the prerequisite is to release nucleic acids inside the bacteria. The common means to release nucleic acids is the chemical method, which involves complex processes, is time-consuming, and remains chemical inhibitors. Compared with chemical methods, electroporation as a physical method has the advantages of easy operation, short-time consumption, and chemical reagents free. However, the current works using electroporation often necessitates high-frequency or high-voltage conditions, entailing bulky power devices. Herein, we propose a low-voltage alternant direct current (LADC) electroporation chip and the corresponding miniature device for ultrafast releasing the genome DNA from Helicobacter pylori (H. pylori) for detection. We connected a micrometer-interdigital electrode in the chip with a 20 V portable battery to make the miniature device. Using this low-voltage device, our chip released genome DNA of H. pylori within only 5 ms, achieving a cell lysis rate of 99.5%. We further combined this chip with a colorimetric loop-mediated isothermal amplification assay to visually detect H. pylori within ~ 25 min at 10 CFU/µL. We detected 11 clinical samples using the chip, and the detection results were consistent with those of the clinical standard. The results indicate that the LADC electroporation chip is useful for ultrafast release of genome DNA from bacteria and is expected to promote the development of nucleic acid detection in POCT and other scenarios.

Rapid On-Site Detection of SARS-CoV-2 Using RT-LAMP Assay with a Portable Low-Cost Device.

Emerging infectious diseases pose a serious threat to human health and affect social stability. In recent years, the epidemic situation of emerging infectious diseases is very serious; among these infectious diseases, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has affected many countries and regions in a short time. The prevention and treatment of these diseases require rapid on-site detection methods. However, the common detection method, RT-PCR, requires expensive instruments, complex operations, and professional operators. Here, we developed a portable low-cost assay for rapid on-site detection of viral nucleic acid using reverse transcription-loop-mediated isothermal amplification (RT-LAMP). The SARS-CoV-2 RNA can be successfully amplified within 15 min in a thermos, and the detection result is read rapidly in a portable low-cost device with a sensitivity of 100 copies/µL. The portable low-cost device consists of a black box, a laser or LED and a filter, costing only a few cents. The rapid on-site detection method can provide strong support for the control of biological threats such as infectious diseases. It is also an emergency detection method for low-resource settings, relieving the huge pressure on health care.

Au@Ag Nanorods-PDMS Wearable Mouthguard as a Visualized Detection Platform for Screening Dental Caries and Periodontal Diseases.

The development of easy-to-use, low-cost, and visualized detection platforms for screening human dental caries and periodontal diseases is in urgent demand. In this work, a Au@Ag nanorods-poly(dimethylsiloxane) (Au@Ag NRs-PDMS) wearable mouthguard, which can visualize the tooth lesion sites through the color change of it at the corresponding locations, is presented. The Au@Ag NRs-PDMS composite exhibits a distinct color response to hydrogen sulfide (H2 S) gas generated by bacterial decay at the lesion sites. Moreover, the Au@Ag NRs-PDMS mouthguard is demonstrated to own desired mechanical properties, excellent chemical stability, as well as good biocompatibility, and can accurately locate the lesion sites in human oral cavity. These findings suggest that the mouthguard has the potential to be utilized on a large scale to help people self-monitor their oral health in daily life, and treat oral diseases locally.

Metaoptronic Multiplexed Interface for Probing Bioentity Behaviors.

Biointerface sensors have brought about remarkable advances in modern biomedicine. To accurately monitor bioentity's behaviors, biointerface sensors need to capture three main types of information, which are the electric, spectroscopic, and morphologic signals. Simultaneously obtaining these three types of information is of critical importance in the development of future biosensor, which is still not possible in the existing biosensors. Herein, by synergizing metamaterials, optical, and electronic sensing designs, we proposed the metaoptronic multiplexed interface (MMI) and built a MMI biosensor which can collectively record electric, spectroscopic, and morphologic information on bioentities. The MMI biosensor enables the real-time triple-monitoring of cellular dynamics and opens up the possibility for powerlessly monitoring ocular dryness. Our findings not only demonstrate an advanced multiplexed biointerface sensor with integrated capacities but also help to identify a uniquely significant arena for the nanomaterials, meta-optics, and nanotechnologies to play their roles in a complementary manner.

Reciprocating-flowing on-a-chip enables ultra-fast immunobinding for multiplexed rapid ELISA detection of SARS-CoV-2 antibody.

The worldwide epidemic of novel coronavirus disease (COVID-19) has led to a strong demand for highly efficient immunobinding to achieve rapid and accurate on-site detection of SARS-CoV-2 antibodies. However, hour-scale time-consumption is usually required to ensure the adequacy of immunobinding on expensive large instruments in hospitals, and the common false negative or positive results often occur in rapid on-site immunoassay (e.g. immunochromatography). We solved this dilemma by presenting a reciprocating-flowing immunobinding (RF-immunobinding) strategy. RF-immunobinding enabled the antibodies in fluid contacting with the corresponding immobilized antigens on substrate repeatedly during continuous reciprocating-flowing, to achieve adequate immunobinding within 60 s. This strategy was further developed into an immunoassay method for the serological detection of 13 suspected COVID-19 patients. We obtained a 100% true negative and true positive rate and a limit of quantification (LOQ) of 4.14 pg/mL. Our strategy also can be a potential support for other areas related to immunorecognition, such as proteomics, immunopharmacology and immunohistochemistry.

A Transparent, Wearable Fluorescent Mouthguard for High-Sensitive Visualization and Accurate Localization of Hidden Dental Lesion Sites.

Accurate detection and early diagnosis of oral diseases such as dental caries and periodontitis, can be potentially achieved by detecting the secretion of volatile sulfur compounds (VSCs) in oral cavities. Current diagnostic approaches for VSCs can detect the existence and concentrations, yet are not capable of locating the dental lesion sites. Herein, the development of a unique approach for accurately locating dental lesion sites using a fluorescent mouthguard consisting of the zinc oxide-poly(dimethylsiloxane) (ZnO-PDMS) nanocomposite to detect the local release of VSCs is reported. The ZnO-PDMS mouthguard displays a highly sensitive and selective response to VSCs, and exhibits high fluorescent stability, good biocompatibility, and low biological toxicity in normal physiological environments. Then, the wearable ZnO-PDMS mouthguard is demonstrated to be able to identify the precise locations of lesion sites in human subjects. Combined with image analysis, the mouthguards successfully uncover the precise locations of dental caries, allowing convenient screening of hidden dental lesion sites that are oftentimes omitted by dentists. Due to low cost, long-term stability, and good patient compliance, the proposed wearable mouthguard is suitable for large-scale production and enables widely applicable, preliminary yet accurate screening of dental lesions prior to dental clinics and routine physical examinations.

Plasmon-Emitter Hybrid Nanostructures of Gold Nanorod-Quantum Dots with Regulated Energy Transfer as a Universal Nano-Sensor for One-step Biomarker Detection.

Recently, biosensing based on weak coupling in plasmon-emitter hybrid nanostructures exhibits the merits of simplicity and high sensitivity, and attracts increasing attention as an emerging nano-sensor. In this study, we propose an innovative plasmon-regulated fluorescence resonance energy transfer (plasmon-regulated FRET) sensing strategy based on a plasmon-emitter hybrid nanostructure of gold nanorod-quantum dots (Au NR-QDs) by partially modifying QDs onto the surfaces of Au NRs. The Au NR-QDs showed good sensitivity and reversibility against refractive index change. We successfully employed the Au NR-QDs to fabricate nano-sensors for detecting a cancer biomarker of alpha fetoprotein with a limit of detection of 0.30 ng/mL, which displays that the sensitivity of the Au NR-QDs nano-sensor was effectively improved compared with the Au NRs based plasmonic sensing. Additionally, to demonstrate the universality of the plasmon-regulated FRET sensing strategy, another plasmon-emitter hybrid nano-sensor of Au nano-prism-quantum dots (Au NP-QDs) were constructed and applied for detecting a myocardial infarction biomarker of cardiac troponin I. It was first reported that the change of absorption spectra of plasmonic structure in a plasmon-emitter hybrid nanostructure was employed for analytes detection. The plasmon-regulated FRET sensing strategy described herein has potential utility to develop general sensing platforms for chemical and biological analysis.