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Human environmental DNA (eDNA) application have not been fully applied or adequately considered in the fields of eDNA and forensics. Nonetheless, this technique holds great potential as a complementary tool for detecting human DNA in aquatic environments, particularly in cases involving crimes connect to such environments. However, the detectability or stability of eDNA can vary depending on several factors. Therefore, this preliminary study investigates the detection and degradation rates of human eDNA, as well as the recovery of nuclear short tandem repeat (STR) profiles and mitochondrial DNA (mtDNA) sequencing, using water samples from both saltwater and freshwater sources. To conduct the experiment, whole human blood was spiked into the water samples. Water samples were then filtered using a 5 µm pore size filter, and samples were collected at various time intervals up to 23 days. A human specific qPCR assay targeting HV1 region of human mtDNA was used to detect human eDNA. Results demonstrated that human eDNA remains detectable for up to 36 hours in freshwater samples and up 84 hours in saltwater samples. The limit of detection (LOD) of human eDNA, (205 copies/µl), was achieved after 60 hours in freshwater and 180 hours in saltwater samples. Partial STR profiles could be recovered up to 24 hours for freshwater and saltwater. Results from mtDNA sequencing indicate that full mtDNA profiles could be recovered from freshwater samples up to 48 hours and remained detectable up to 72 hours in saltwater. Overall, the findings of this study underscore the importance of considering and incorporating human eDNA analysis as a valuable tool in forensic practice. By harnessing the power of eDNA, law enforcement agencies can enhance their investigation capabilities, improve the accuracy of forensic reconstructions, and ultimately contribute to the resolution of cases involving aquatic environments. Further research and validation are needed to optimize and expand the utilization of eDNA techniques in forensic investigations., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The identification of biological fluids at crime scenes contributes to crime scene reconstruction and provides investigative leads. Traditional methods for body fluid identification are limited in terms of sensitivity and are mostly presumptive. Emerging methods based on mRNA and DNA methylation require high quality template source. An exploitable characteristic of body fluids is their distinct microbial profiles allowing for the discrimination of body fluids based on microbiome content. Microbial DNA is highly abundant within the body, robust and stable and can persist in the environment long after human DNA has degraded. 16S rRNA sequencing is the gold standard for microbial analysis; however, NGS is costly, and requires intricate workflows and interpretation. Also, species level resolution is not always achievable. Based on the current challenges, the first objective of this study was to develop a multiplex conventional PCR assay to identify vaginal fluid and saliva by targeting species-specific 16S rRNA microbial markers. The second objective was to employ droplet digital PCR (ddPCR) as a novel approach to quantify bacterial species alone and in a mixture of body fluids. Lactobacillus crispatus and Streptococcus salivarius were selected because of high abundance within vaginal fluid and saliva respectively. While Fusobacterium nucleatum and Gardnerella vaginalis, though present in healthy humans, are also frequently found in oral and vaginal infections, respectively. The multiplex PCR assay detected L. crispatus and G. vaginalis in vaginal fluid while F. nucleatum and S. salivarius was detected in saliva. Multiplex PCR detected F. nucleatum, S. salivarius and L. crispatus in mixed body fluid samples while, G. vaginalis was undetected in mixtures containing vaginal fluid. For samples exposed at room temperature for 65 days, L. crispatus and G. vaginalis were detected in vaginal swabs while only S. salivarius was detected in saliva swabs. The limit of detection was 0.06 copies/µl for F. nucleatum (2.5 ×10 -9 ng/µl) and S. salivarius (2.5 ×10 -6 ng/µl). L. crispatus and G. vaginalis had detection limits of 0.16 copies/µl (2.5 ×10 -4 ng/µl) and 0.48 copies/µl (2.5 ×10 -7 ng/µl). All 4 bacterial species were detected in mixtures and aged samples by ddPCR. No significant differences were observed in quantity of bacterial markers in saliva and vaginal fluid. The present research reports for the first time the combination of the above four bacterial markers for the detection of saliva and vaginal fluid and highlights the sensitivity of ddPCR for bacterial quantification in pure and mixed body fluids., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Colloidal self-assembly allows rational design of structures on the micrometer and submicrometer scale. One architecture that can generate complete three-dimensional photonic bandgaps is the diamond cubic lattice, which has remained difficult to realize at length scales comparable with the wavelength of visible or ultraviolet light. In this work, we demonstrate three-dimensional photonic crystals self-assembled from DNA origami that act as precisely programmable patchy colloids. Our DNA-based nanoscale tetrapods crystallize into a rod-connected diamond cubic lattice with a periodicity of 170 nanometers. This structure serves as a scaffold for atomic-layer deposition of high-refractive index materials such as titanium dioxide, yielding a tunable photonic bandgap in the near-ultraviolet.

The combination of lithographic methods with two-dimensional DNA origami self-assembly has led, among others, to the development of photonic crystal cavity arrays and the exploration of sensing nanoarrays where molecular devices are patterned on the sub-micrometre scale. Here we extend this concept to the third dimension by mounting three-dimensional DNA origami onto nanopatterned substrates, followed by silicification to provide hybrid DNA-silica structures exhibiting mechanical and chemical stability and achieving feature sizes in the sub-10-nm regime. Our versatile and scalable method relying on self-assembly at ambient temperatures offers the potential to three-dimensionally position any inorganic and organic components compatible with DNA origami nanoarchitecture, demonstrated here with gold nanoparticles. This way of nanotexturing could provide a route for the low-cost production of complex and three-dimensionally patterned surfaces and integrated devices designed on the molecular level and reaching macroscopic dimensions., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

In view of WHO's "End-TB" strategy, we developed a non-invasive, urine-based ELISA, targeting 2 Mycobacterium tuberculosis antigens namely MPT51 and MPT64 for extrapulmonary TB (EPTB) diagnosis. Suspected EPTB patients (n = 137) [Pleural TB, Abdominal TB and Tuberculous meningitis] were categorized in "Definite" EPTB (n = 10) [Xpert-MTB/RIF and/or culture-positive], "Probable" EPTB (n = 77) and "Non-EPTB" (n = 50) groups using defined composite reference standards. ROC-curves were generated using ELISA results of "Definite" EPTB and "Non-EPTB" groups for both antigens independently and cut-off values were selected to provide 86.3% (95%CI:73.3-94.2) specificity for MPT51 and 92% (95%CI:80.8-97.8) for MPT64. The sensitivity of MPT51-ELISA and MPT64-ELISA was 70% (95%CI:34.7-93.3) and 90% (95%CI:55.5-99.7) for "Definite" EPTB group and 32.5% (95%CI:22.2-44.1) and 30.8% (95%CI:20.8-42.2) for "Probable" EPTB group, respectively. Combining the results of both ELISAs showed a 100% (95%CI:69.1-100) sensitivity in "Definite" EPTB group and 41.6% (95%CI:30.4-53.4) in "Probable" EPTB group, with an 80% (95%CI:66.3-89.9) specificity. The results demonstrated the potential of urine-based ELISAs as screening tests for EPTB diagnosis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)