A ratiometric fluorescence platform was developed based on the cobalt oxyhydroxide (CoOOH) nanosheet–modulated fluorescence response of blue emissive copper nanoclusters (Cu NCs) and yellow emissive o-phenylenediamine (OPD). CoOOH nanosheets showed dual function of strong absorption and oxidation ability, which can effectively quench the blue fluorescence of Cu NCs, with an excitation and emission peak maximum at 390 and 450 nm, respectively , and transfer the OPD into yellow fluorescence products, with an excitation and emission peak maximum at 390 and 560 nm, respectively. Upon introducing butyrylcholinesterase (BChE) and its substrates, CoOOH nanosheets were decomposed into Co2+, and malachite green (MG) showed strong inhibition ability to this process. This resulted in the obvious difference on the ratio of blue and yellow fluorescence recorded on the system in the presence and absence of MG, which was utilized for the quantitative detection of MG, with a limit of detection of 0.140 μM and a coefficient of variation of 3.5

Uracil-DNA glycosylase (UDG) plays a crucial role in the removal of damaged uracil bases, thereby upholding genetic stability and integrity. An enzyme-powered, label-free DNA walker was devised for UDG activity detection. Initially, a label-free DNA track, incorporating a gold nanoparticle (AuNP), multiple hairpin structures, and various swing arms, was engineered for walking mechanism. The hairpin structure was meticulously crafted to include a G-quadruplex sequence, enabling the generation of a label-free fluorescence signal. The swing arm remained inert in the absence of UDG, but became activated upon the introduction of UDG, thereby initiating the enzyme-powered walking process and generating significant dissociative G-quadruplex sequences. By integrating a selective fluorescent dye into the design, an enhanced label-free fluorescence response was achieved. The proposed DNA walker presented a direct and label-free approach for UDG detection, demonstrating exceptional sensitivity with a detection limit of 0.00004 U/mL. Using the uracil glycosylase inhibitor (UGI) as an inhibitory model, inhibitor assay was conducted with satisfactory precision. Furthermore, successful analysis of cellular UDG at the single-cell level was accomplished. Consequently, the developed DNA walker serves as a label-free, selective, and sensitive tool for UDG activity assessment, showing great potential for applications in disease diagnosis, inhibitor screening, and biomedical investigations.

Transcription-polymerase chain reaction (RT-qPCR) is the golden standard to detect viral RNA. However, it suffers from several inherent defects such as high false-negative rates, time-consuming and expensive. To exploit better analytical methods for future global pandemics, it is vital to develop rapid, sustainable, and environmentally-friendly sensing methods. Here, a one-step, regenerated nanosensor assembled by DNA tweezers is developed for rapid and sustainable detection of viral RNA. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA is selected as model analyte. The DNA tweezer is designed with a central strand and two arm strands containing overhangs complementary to SARS-CoV-2 RNA. The SARS-CoV-2 RNA hybridizes with the two arm overhangs and strains the DNA tweezer to closed conformation, resulting in the close proximity of the donor and acceptor fluorophores. With the addition of an anti-strand complementary to the SARS-CoV-2 RNA, the closed DNA tweezer is relaxed to open conformation through a strand displacement process, leading to the separation of the dual fluorophores. Thus, the DNA tweezer is revived for fresh SARS-CoV-2 RNA. The proposed nanosensor can be regenerated for three cycles with the same performance. Moreover, the viral RNA can be detected within 30 min with a detection limit of 0.04 nM. By altering the sequences of the DNA tweezer, rapid, sensitive, and sustainable detection of Hg 2 + is achieved. The proposed nanosensor provides a novel approach for rapid, flexible, and sustainable detection of viral RNA and Hg 2 + , exhibiting great potential for routine preliminary coronavirus disease tests, epidemic control, and environmental monitoring.

The quantitative detection and discrimination of glutathione (GSH) were achieved based on oxalyl dihydrazide (ODH) decorated sulfur nanodots. ODH resulted in the aggregation and fluorescence quenching of the sulfur nanodots, and GSH selectively triggered fluorescence recovery through forming stronger hydrogen bonds with ODH than other biological thiols. The quantitative detection and discrimination of glutathione (GSH) were achieved based on oxalyl dihydrazide (ODH) decorated sulfur nanodots.

In multimodal multi-objective optimization, the key issue is to find as many Pareto optimal solutions as possible and select promising solutions in the environmental selection. This paper proposes a multimodal multi-objective particle swarm optimization algorithm based on multi-directional guidance (MM-PSO-MG) to solve these problems. In the proposed algorithm, multi-directional guidance strategy is introduced to avoid premature convergence and find more Pareto optimal solutions. Moreover, the rank-based special crowding distance strategy is used to select promising solutions. 11 multimodal multi-objective test problems are used to verify the performance of the proposed algorithm. The results show that the proposed algorithm is competitive.

Introduction Emerging evidence has suggested that inherited factors are also involved in lung cancer development. However, most studies focused on well-elucidated cancer predisposition genes, the majority of which are tumor suppressor genes. The profile of germline mutations in oncogenic driver genes remains unrevealed, which might also provide potential clinical implications for lung cancer management. Methods Sequencing data from 36,813 unselected lung cancer patients who underwent somatic mutation profiling were retrospectively reviewed. All recruited patients had matched white blood cell samples sequenced in parallel using a capture-based panel including eight key lung cancer driver genes (epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), MET proto-oncogene, receptor tyrosine kinase (MET), Kirsten rat sarcoma viral oncogene homolog (KRAS), Erb-B2 receptor tyrosine kinase 2(ERBB2), ROS proto-oncogene 1, receptor tyrosine kinase (ROS1), ret proto-oncogene (RET), and B-Raf proto-oncogene, serine/threonine kinase (BRAF)). Likely pathogenic/pathogenic (LP/P) variants were called according to the classification criteria of the American College of Medical Genetics and Genomics. Variants of uncertain significance (VUS) located in the kinase domains of driver genes and occurring recurrently (n ≥3) were also included for further analyses. Results Seven different LP/P variants in EGFR, MET, or RET were identified in 0.03% of lung cancer patients (n = 14) and 25 different VUS in the kinase domains of seven driver genes (except KRAS) were found with a prevalence of 0.3% (n = 117).Collectively, germline mutations were most frequently seen in ROS1 (n = 31, 0.084%), followed by MET (n = 23, 0.062%), EGFR (n = 22, 0.06%), ALK (n = 22, 0.06%) and RET (n = 17, 0.046%). LP/P variants and VUS fell the most commonly in EGFR (n = 10, 72%) and ROS1 (n = 31, 26%), respectively. Of the 10 patients with EGFR LP/P germline mutation, 70% also acquired somatic EGFR driver mutation exon21 p.L858R or exon19 deletion at baseline; while the three patients with pathogenic germline RET mutation displayed distinct baseline somatic profiles of rare EGFR mutation or KRAS exon2 p.G12C. We discovered 11 germline mutations that also occurred somatically, including four LP/P variants and seven VUS. Conclusion We present the first study to systemically characterize the germline mutation in oncogenic driver genes in a large cohort of unselected patients with lung cancers.

Cholinesterases (ChEs) are important indicators of neurological disease, hepatocellular carcinoma, and organophosphate poisoning. In this work, a MnO2 switch-bridged DNA walker was developed for ultrasensitive sensing of ChEs activity. The fuel strands loaded MnO2 switch was designed to bridge the hydrolysis activity of ChEs and the running of the DNA walker. Under the action of ChE, the substrate butyrylcholine is first catalytically hydrolyzed to thiocholine, which then mediates MnO2 nanosheet reduction to Mn2+, releasing the fuel strands into solution. The fuel strands as substitute targets then trigger the continuous operation of DNA walker with the aid of Mn2+, generating detectable fluorescence responses. The detection of ChE activity is converted to DNA detection in this method. Benefited from the robust operation and amplification effect of DNA walker, a wide linear range between the BChE activity and fluorescence intensity of nearly six orders of magnitude (1000-0.005 U/mL) and a limit of detection as low as 0.0008 U/mL are achieved. This allows the direct determination of BChE activity in clinical serum samples without any pretreatments. Moreover, the proposed method has remarkable capabilities for inhibitor (organophosphorus pesticide) screening and quantification, and organophosphorus pesticide detection in real samples is also achieved. Therefore, the MnO2 switch-bridged DNA walker represents a powerful tool for ultrasensitive sensing of ChEs and organophosphorus pesticides, and has great application potential in clinical diagnosis, therapeutics, and drug screening.

Visually observable pH-responsive luminescent materials are developed by integrating the properties of aggregation-induced emission enhancement of Cu nanoclusters (NCs) and the Ca2+-triggered gelatin of alginate. Sodium alginate, CaCO3 nanoparticles, and Cu NCs are dispersed in aqueous solution, which is in a transparent fluid state, showing weak photoluminescence (PL). The introduced H+ can react with the CaCO3 nanoparticles to produce free Ca2+, which can cross-link the alginate chains into gel networks. Meanwhile, a dramatic increase in the PL intensity of Cu NCs and a blue shift in the PL peak appeared, assigned to the Ca2+-induced enhancement and gelatin-induced enhancement, respectively. Their potential application as a sensor for glucose is also demonstrated based on the principle that glucose oxidase can recognize glucose and produce H+, which further triggers the above-mentioned two-stage enhancement. A linear relationship between the PL intensity and the concentration of glucose in the range of 0.1-2.0 mM is obtained, with the limit of detection calculated as 3.2 × 10-5 M.

A smart DNA tweezer was constructed for universal proximity assay and logic building. In this tweezer, the set strand was designed as recognition module, and the ends of two motifs were ingeniously designed as toehold domain (TD) and branch migration domain (BMD). As the recognition of set strand and target, the set strand could be dismantled from the tweezer, resulting in a proximity binding of TD and BMD. Then, the proximal TD and BMD could initiate the dynamic assembly of two complementary hairpins, yeilding a long double-stranded polymer with multiple G-quadruplexes. By inserting fluorescent dye, enhanced fluorescent response could be observed. Universal and sensitive assay of miRNA and thrombin were achieved by altering the sequence of set strand. The corresponding detection limits were 9.4 fM and 0.35 pM. Moreover, quantitative analysis of miRNA in clinical serum sample was also performed, suggesting the feasibility of this proximity assay in clinical application. What's more, based on the proposed DNA tweezer, a Boolean logic operation platform was fabricated, and systematic logic operations were also achieved. Therefore, this work provided a reliable strategy for universal proximity assay and logic operation, which could be further used in biomedical research and clinical diagnosis.

Hydrogen sulfide (H2S) is an important endogenous gaseous signaling molecule with multiple biological functions. In this study, an NBD-based ratiometric fluorescent probe (MR-1) was successfully designed and synthesized for selectively detection H2S. The probe exhibits high selectivity and fast emission intensity ratio changes in response to H2S in solution. The modification of triphenylphosphine in the probe enables it to be used for the imaging mitochondrial H2S in living HeLa cells.

In this study, a regenerated nanotweezer-managed catalytic DNA circuit was constructed. A nanotweezer with two crossover motifs was assembled using 10 oligonucleotides, a toehold domain (TD), and a branch migration domain (BMD) as the two motifs of the nanotweezer. In the absence of a catalyst, the nanotweezer was opened, the TD and the BMD were separated with few catalytic activities. Upon catalyst addition, the set strand in the nanotweezer was liberated, forming a closed nanotweezer with proximal binding of the TD and the BMD with catalytic activity. Subsequently, the TD/BMD initiated the cyclic catalytic assembly of DNA hairpins, forming a DNA circuit. By re-introducing some set sequences, the nanotweezer and TD/BMD could be switched back to the opened state, and the progress of catalytic DNA circuit could be stopped and managed. By re-adding fresh catalysts, the stopped circuit could be re-initiated through regeneration of the closed nanotweezer. Thus, a controllable and flexible DNA circuit was achieved with sensitive and quantitative detection of cancer-related miRNA and uracil-DNA glycosylase (UDG) in complex biological samples. The novel system provid a flexible and reliable DNA circuit for biological detection, clinical diagnosis, and biomedical research.

通过生物偶联方式,将无毒的碳点（Carbon Dots,CD）表面功能化上核酸,以核酸功能化的碳点（CD-DNA）为荧光团,氧化石墨烯（GO）为猝灭剂,二者组装成CD-DNA/GO纳米荧光探针,CD与GO之间产生长程共振能量转移（long-range resonance energy transfer,LrRET）,CD荧光猝灭。当miRNA-21存在时,DNA与其杂交,CD从GO表面分离,二者之间的荧光共振能量转移被打断,碳点荧光恢复,通过荧光"开"方式检测miRNA-21,检测限为0.2nmol/L,线性范围为1~500nmol/L。该探针成功应用于血癌K562细胞中miRNA-21的原位成像,为血癌的原位诊断和治疗提供了研究依据。