Pub Date : 2021-11-30DOI: 10.26434/chemrxiv-2021-m9clp
Huishan Li, Nicholas Allen, Mengtian Li, Anyin Li
Femto flow electrospray ionization (ESI) with flow rates ranging from 240 fL min-1 to the low pico level (<10 pL min-1) was conducted and measured using a submicron emitter tip and relay ESI configuration. Signature analyte ion current intensities and profiles were observed. The obtained flow rate and ionization current enabled size calculation for initial charged nanodroplets.
{"title":"Conducting and characterizing femto flow electrospray ionization.","authors":"Huishan Li, Nicholas Allen, Mengtian Li, Anyin Li","doi":"10.26434/chemrxiv-2021-m9clp","DOIUrl":"https://doi.org/10.26434/chemrxiv-2021-m9clp","url":null,"abstract":"Femto flow electrospray ionization (ESI) with flow rates ranging from 240 fL min-1 to the low pico level (<10 pL min-1) was conducted and measured using a submicron emitter tip and relay ESI configuration. Signature analyte ion current intensities and profiles were observed. The obtained flow rate and ionization current enabled size calculation for initial charged nanodroplets.","PeriodicalId":82956,"journal":{"name":"The Behavior analyst","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88097839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-05DOI: 10.33774/chemrxiv-2021-kvtmv
Rhiannon E Boseley, D. Howard, M. Hackett, S. Lewis
In forensic science, knowledge and understanding of material transfer and persistence is inherent to the interpretation of trace evidence and can provide vital information on the activity level surrounding a crime. Detecting metal ions in fingermark residue has long been of interest in the field of forensic science, due to the possibility of linking trace metal ion profiles to prior activity with specific metal objects (e.g. gun or explosive handling). Unfortunately, the imaging capability to visualise trace metal ions at sufficient spatial resolution to determine their distribution within a fingermark (micron level) was not previously available. Here, we demonstrate for the first time transfer and persistence of metals in fingermarks, at micron spatial resolution, using synchrotron sourced X-ray fluorescence microscopy. Such information may form a critical baseline for future metal-based detection strategies. Fingermarks were taken before and after brief handling of a gun barrel, ammunition cartridge case and party sparkler to demonstrate the transfer of metals. The results reveal increased metal content after contact with these objects, and critically, a differential pattern of metal ion increase was observed after handling different objects. Persistence studies indicate that these metals are removed as easily as they are transferred, with a brief period of hand washing appearing to successfully remove metallic residue from subsequent fingermarks. Preliminary work using X-ray absorption near edge structure spectroscopic mapping highlighted the potential use of this technique to differentiate between different chemical forms of metals and metal ions in latent fingermarks. It is anticipated that these findings can now be used to assist future work for the advancement of trace metal detection tests and fingermark development procedures.
{"title":"The transfer and persistence of metals in latent fingermarks.","authors":"Rhiannon E Boseley, D. Howard, M. Hackett, S. Lewis","doi":"10.33774/chemrxiv-2021-kvtmv","DOIUrl":"https://doi.org/10.33774/chemrxiv-2021-kvtmv","url":null,"abstract":"In forensic science, knowledge and understanding of material transfer and persistence is inherent to the interpretation of trace evidence and can provide vital information on the activity level surrounding a crime. Detecting metal ions in fingermark residue has long been of interest in the field of forensic science, due to the possibility of linking trace metal ion profiles to prior activity with specific metal objects (e.g. gun or explosive handling). Unfortunately, the imaging capability to visualise trace metal ions at sufficient spatial resolution to determine their distribution within a fingermark (micron level) was not previously available. Here, we demonstrate for the first time transfer and persistence of metals in fingermarks, at micron spatial resolution, using synchrotron sourced X-ray fluorescence microscopy. Such information may form a critical baseline for future metal-based detection strategies. Fingermarks were taken before and after brief handling of a gun barrel, ammunition cartridge case and party sparkler to demonstrate the transfer of metals. The results reveal increased metal content after contact with these objects, and critically, a differential pattern of metal ion increase was observed after handling different objects. Persistence studies indicate that these metals are removed as easily as they are transferred, with a brief period of hand washing appearing to successfully remove metallic residue from subsequent fingermarks. Preliminary work using X-ray absorption near edge structure spectroscopic mapping highlighted the potential use of this technique to differentiate between different chemical forms of metals and metal ions in latent fingermarks. It is anticipated that these findings can now be used to assist future work for the advancement of trace metal detection tests and fingermark development procedures.","PeriodicalId":82956,"journal":{"name":"The Behavior analyst","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90664078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-01DOI: 10.33774/chemrxiv-2021-nl537
Gabriele Selvaggio, R. Nissler, P. Nietmann, A. Patra, Lukas J. Patalag, A. Janshoff, D. Werz, S. Kruss
Near-infrared (NIR) fluorophores are emerging tools for biophotonics because of their reduced scattering, increased tissue penetration and low phototoxicity. However, the library of NIR fluorophores is still limited. Here, we report the NIR fluorescence of two benzene-fused oligo-BODIPYs in their hexameric (H) and octameric (O) forms. These dyes emit bright NIR fluorescence (H: maxima 943/1075 nm, O: maxima 976/1115 nm) that can be excited in the NIR (H = 921 nm, O = 956 nm) or non-resonantly over a broad range in the visible region. The emission bands of H show a bathochromic shift and peak sharpening with increasing dye concentration. Furthermore, the emission maxima of both H and O shift up to 20 nm in solvents of different polarity. These dyes can be used as NIR ink and imaged remotely on the macroscopic level with a stand-off distance of 20 cm. We furthermore demonstrate their versatility for biophotonics by coating microscale beads and performing microrheology via NIR video particle tracking (NIR-VPT) in biopolymer (F-actin) networks. No photodamaging of the actin filaments takes place, which is typically observed for visible fluorophores and highlights the advantages of these NIR dyes.
{"title":"NIR-emitting benzene-fused oligo-BODIPYs for bioimaging.","authors":"Gabriele Selvaggio, R. Nissler, P. Nietmann, A. Patra, Lukas J. Patalag, A. Janshoff, D. Werz, S. Kruss","doi":"10.33774/chemrxiv-2021-nl537","DOIUrl":"https://doi.org/10.33774/chemrxiv-2021-nl537","url":null,"abstract":"Near-infrared (NIR) fluorophores are emerging tools for biophotonics because of their reduced scattering, increased tissue penetration and low phototoxicity. However, the library of NIR fluorophores is still limited. Here, we report the NIR fluorescence of two benzene-fused oligo-BODIPYs in their hexameric (H) and octameric (O) forms. These dyes emit bright NIR fluorescence (H: maxima 943/1075 nm, O: maxima 976/1115 nm) that can be excited in the NIR (H = 921 nm, O = 956 nm) or non-resonantly over a broad range in the visible region. The emission bands of H show a bathochromic shift and peak sharpening with increasing dye concentration. Furthermore, the emission maxima of both H and O shift up to 20 nm in solvents of different polarity. These dyes can be used as NIR ink and imaged remotely on the macroscopic level with a stand-off distance of 20 cm. We furthermore demonstrate their versatility for biophotonics by coating microscale beads and performing microrheology via NIR video particle tracking (NIR-VPT) in biopolymer (F-actin) networks. No photodamaging of the actin filaments takes place, which is typically observed for visible fluorophores and highlights the advantages of these NIR dyes.","PeriodicalId":82956,"journal":{"name":"The Behavior analyst","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75810571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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