Nicole Serio

Cyclodextrin-Enhanced Extraction and Energy Transfer of Carcinogens in Complex Oil Environments

Reported herein is the use of γ-cyclodextrin for two tandem functions: (a) the extraction of carcinogenic polycyclic aromatic hydrocarbons (PAHs) from oil samples into aqueous solution and (b) the promotion of highly efficient energy transfer from the newly extracted PAHs to a high-quantum-yield fluorophore. The extraction proceeded in moderate to good efficiencies, and the resulting cyclodextrin-promoted energy transfer led to a new, brightly fluorescent signal in aqueous solution. The resulting dual-function system (extraction followed by energy transfer) has significant relevance in the environmental detection and cleanup of oil-spill-related carcinogens.

Cyclodextrin-promoted energy transfer for broadly applicable small-molecule detection

Reported herein is the development of non-covalent, proximity-induced energy transfer from small-molecule toxicants to organic fluorophores bound in the cavity of γ-cyclodextrin. This energy transfer occurs with exceptional efficiency for a broad range of toxicants in complex biological media, and is largely independent of the spectral overlap between the donor and acceptor. This generally applicable phenomenon has significant potential in the development of new turn-on detection schemes.

Detection of Medium-Sized Polycyclic Aromatic Hydrocarbons via Fluorescence Energy Transfer

Reported herein is the use of proximity-induced non-covalent energy transfer for the detection of medium-sized polycyclic aromatic hydrocarbons (PAHs). This energy transfer occurs within the cavity of γ-cyclodextrin in various aqueous environments, including human plasma and coconut water. Highly efficient energy transfer was observed, and the efficiency of the energy transfer is independent of the concentration of γ-cyclodextrin used, demonstrating the importance of hydrophobic binding in facilitating such energy transfer. Low limits of detection were also observed for many of the PAHs investigated, which is promising for the development of fluorescence-based detection schemes.

Efficient extraction and detection of aromatic toxicants from crude oil and tar balls using multiple cyclodextrin derivatives

Herein we report the efficient extraction of aromatic analytes from crude oil and tar balls using multiple cyclodextrin derivatives. The known propensity of the cyclodextrins to bind hydrophobic guests in their hydrophobic interiors enhanced the extraction of aromatic analytes from the oil layer to the aqueous layer, with methyl-β-cyclodextrin and β-cyclodextrin providing the most significant enhancement in extraction efficiencies of aromatic toxicants (69% aromatic toxicants in aqueous layer in the presence of methyl-β-cyclodextrin compared to 47% in cyclodextrin-free solution for tar ball oil extraction), and provide optimal tunability for developing efficient extraction systems. The cyclodextrin derivatives also promoted efficient energy transfer in the aqueous solutions, with up to 86% efficient energy transfer observed in the presence of γ-cyclodextrin compared to 50% in the absence of cyclodextrin for oil spill oil extraction. Together, this dual function extraction followed by detection system has potential in the development of environmental remediation systems.

2-Hydroxypropyl beta-cyclodextrin for the enhanced performance of dual function extraction and detection systems in complex oil environments

The use of 2-hydroxypropyl-β-cyclodextrin (2-HPCD) for the tandem extraction and proximity-induced energy transfer based detection of carcinogenic polycyclic aromatic hydrocarbons (PAHs) is described herein. Previous work investigated γ-cyclodextrin for this purpose, but the lower cost and reduced toxicity of 2-HPCD made it an attractive target for investigation. 2-HPCD was found to be highly efficient in the extraction of PAHs from oil samples, but was equally or slightly less efficient in promoting intra-cavity energy transfer to a high quantum yield fluorophore. The detection of PAHs via this system results in a new fluorescent signal that can be used to identify different PAHs in aqueous solution. This dual-function system can be very beneficial for oil spill remediation efforts.

Cyclodextrin-Promoted Detection of Aromatic Toxicants and Toxicant Metabolites in Urine

Abstract Reported herein is the development of a fluorescence-based detection method for aromatic toxicants and toxicant metabolites in urine, using cyclodextrin-promoted energy transfer to high quantumyield fluorophores. This method distinguishes smoker urine from non-smoker urine, enables highly accurate analyte identification, and leads to micromolar detection limits.

Efficient fluorescence detection of aromatic toxicants and toxicant metabolites in human breast milk

Abstract Once chemical contaminants are released into the environment, there are a number of concerns that arise regarding the environmental persistence of the contaminants, their known and suspected toxicities, and their potential disruption to the ecosystem. One class of contaminants that is of continuing concern is polycyclic aromatic hydrocarbons (PAHs), persistent organic pollutants that are significant components of oil spills. PAHs have been found in the breast milk of nursing mothers living in oil spill-affected regions, and can harm the nursing children. We report herein the sensitive and selective detection of 10 PAHs and PAH metabolites in human breast milk using fluorescence energy transfer from the PAH to a high quantum yield fluorophore, and array-based statistical analyses of the resulting fluorescence responses. This detection system was able to separate and identify the PAHs with 100% success in human breast milk and at concentrations as low as 0.17 μM. These results have significant implications in public health and in the monitoring and mitigation of environmental disasters.

Solvent effects in the extraction and detection of polycyclic aromatic hydrocarbons from complex oils in complex environments

Anthropogenic oil spills such as the 2010 Deepwater Horizon oil spill present a number of unique challenges in environmental remediation, detection, and monitoring of a wide range of toxicants in complex environments. We have previously reported the use of cyclodextrin derivatives to accomplish the selective extraction of polycyclic aromatic hydrocarbons (PAHs) and facilitate their detection via proximity-induced energy transfer. Reported herein is the ability of these cyclodextrins to operate in a real-world scenario: extracting PAHs from oil collected from an oil spill site and from tar ball extracts into crude seawater from the Narragansett Bay in Rhode Island. The ability of this system to operate in this complex environment highlights the practical significance of cyclodextrin-based systems, and a direct comparison of the results obtained in seawater with those obtained using a variety of aqueous solvent systems provides significant insights into the factors responsible for efficient performance.Graphical Abstract