Quantification of the pH of Aerosol Droplets via Nanoprobe Based Sensing

通过纳米探针传感定量气溶胶液滴的 pH 值

• 批准号: 1705653
• 负责人: Peter Vikesland
• 金额: $ 33万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1705653&HistoricalAwards=false
• 关键词: Quantification; pH; Aerosol; Droplets; via

PI Name: VikeslandProposal Number: 1705653Atmospheric aerosol droplets are well recognized for their capacity to affect both local-scale as well as global air quality. To date, efforts to measure the acidity (or basicity) of aerosols at the individual droplet level have been largely unsuccessful. This effort supports research conducted to quantify droplet acidity (or basicity) using nanotechnology and laser-enabled spectroscopy. The expected results will provide an improved understanding of aerosol droplet chemistry and will thus enhance societal appreciation of the complexity of aerosol interactions. Both undergraduate and graduate students will receive training in advanced spectroscopic methods, and an extensive K-12 outreach effort will be initiated. The primary research goal of this effort is to quantify the pH of micron-scale aerosol droplets and evaluate how it affects droplet chemistry. pH is a defining characteristic of all natural waters; however, the pH of individual aerosolized droplets has not been well established through direct measurements. In this effort recently developed novel nanoprobes will be used to probe pH inside individual micron-scale droplets as well as to investigate the influence of reactive gases on droplet pH. The PIs will take advantage of the spatial sensitivity enabled by gold nanoparticle (AuNP) based probes that are entrained within the confined environment of a 15-40 ìm diameter droplet. By utilizing a nanoscale optical technique--surface enhanced Raman spectroscopy (SERS)--the PIs expect to spectroscopically detect differences in pH in both 2-D and 3-D with ~300 nm resolution. The following three research objectives will be met: Objective 1: Determine the spatial distribution of pH inside micron-scale droplets. Objective 2: Determine how pH changes with relative humidity (RH) as an aerosol is subjected to cycles of efflorescence and deliquescence. Objective 3: Quantify the effect of reactive gases (CO2, SO2, NH3) on droplet pH. Previous studies have established that gaseous pollutants undergo transformations inside aerosol droplets. Many such reactions are pH sensitive, and if the preliminary pH results are correct, these reactions could be either accelerated or decelerated relative to bulk phase expectations. Such an outcome would have a major impact on our understanding of aerosol interactions across many ecosystems. The diverse individuals engaged with this project will contribute to the scientific workforce, but more importantly they will interact with K-12 and other groups via outreach activities organized by the Virginia Tech Sustainable Nanotechnology (VTSuN) program and the NSF-funded NanoEarth Center.

国际和平研究所名称：VikelandProposal编号：1705653大气气溶胶液滴因其影响当地和全球空气质量的能力而得到公认。到目前为止，在单个液滴水平上测量气溶胶的酸度(或碱度)的努力基本上没有成功。这一努力支持了使用纳米技术和激光光谱技术量化液滴酸度(或碱度)的研究。预期的结果将增进对气溶胶微滴化学的了解，从而提高社会对气溶胶相互作用复杂性的认识。本科生和研究生都将接受先进光谱方法的培训，并将启动广泛的K-12推广工作。这项工作的主要研究目标是量化微米级气溶胶液滴的pH值，并评估其对液滴化学的影响。PH值是所有自然水域的一个决定性特征；然而，通过直接测量还没有很好地确定单个气雾化水滴的PH值。在这项工作中，最近开发的新型纳米探针将被用来探测单个微米级液滴的pH，以及研究反应气体对液滴pH的影响。PI将利用基于金纳米颗粒(AuNP)的探测器所带来的空间敏感性，这些探测器被携带在直径15-40？m的受限环境中。通过利用纳米尺度的光学技术--表面增强拉曼光谱(SERS)--PI有望以大约300纳米的分辨率从光谱上检测2-D和3-D的pH值差异。将实现以下三个研究目标：目标1：确定微米级液滴内pH的空间分布。目的：研究气雾剂在风化和潮解过程中，pH值随相对湿度的变化规律。目的：量化反应气体(CO2、SO2、NH3)对液滴pH的影响。以前的研究已经证实，气态污染物在气溶胶液滴中发生转化。许多这样的反应是pH敏感的，如果初步的pH结果是正确的，这些反应可能会加速或减速，相对于主体相预期。这样的结果将对我们理解许多生态系统中的气溶胶相互作用产生重大影响。参与该项目的不同个人将为科学队伍做出贡献，但更重要的是，他们将通过弗吉尼亚理工大学可持续纳米技术(VTSuN)计划和NSF资助的纳米地球中心组织的外联活动与K-12和其他群体互动。

项目成果

In Situ pH Measurement of Water Droplets Using Flash-Freeze Surface-Enhanced Raman Spectroscopy

• DOI: 10.1021/acs.estlett.2c00181
• 发表时间: 2022-05-10
• 期刊: ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
• 影响因子: 10.9
• 作者: Huang, Qishen;Vikesland, Peter J.
• 通讯作者: Vikesland, Peter J.

Nanosensors for water quality monitoring

• DOI: 10.1038/s41565-018-0209-9
• 发表时间: 2018-08-01
• 期刊: NATURE NANOTECHNOLOGY
• 影响因子: 38.3
• 作者: Vikesland, Peter J.

Discriminatory Detection of ssDNA by Surface-Enhanced Raman Spectroscopy (SERS) and Tree-Based Support Vector Machine (Tr-SVM)

• DOI: 10.1021/acs.analchem.0c04576
• 发表时间: 2021-07-01
• 期刊: ANALYTICAL CHEMISTRY
• 影响因子: 7.4
• 作者: Kang, Seju;Kim, Inyoung;Vikesland, Peter J.
• 通讯作者: Vikesland, Peter J.

Implications of the Coffee-Ring Effect on Virus Infectivity

• DOI: 10.1021/acs.langmuir.1c01610
• 发表时间: 2021-09-15
• 期刊: LANGMUIR
• 影响因子: 3.9
• 作者: Huang, Qishen;Wang, Wei;Vikesland, Peter J.
• 通讯作者: Vikesland, Peter J.

Low-Temperature Raman Imaging of Component Distribution in Micron-Size Droplets

微米级液滴成分分布的低温拉曼成像

• DOI: 10.1021/acsearthspacechem.1c00412
• 发表时间: 2022
• 期刊: ACS Earth and Space Chemistry
• 影响因子: 3.4
• 作者: Huang, Qishen;Vikesland, Peter J.
• 通讯作者: Vikesland, Peter J.