Naiying Hao

Bio: Naiying Hao is an academic researcher from Central South University. The author has contributed to research in topics: Chemistry & Thiram. The author has an hindex of 4, co-authored 4 publications receiving 77 citations.

Simultaneous In Situ Extraction and Fabrication of Surface-Enhanced Raman Scattering Substrate for Reliable Detection of Thiram Residue.

Abstract: We report a novel strategy of simultaneous in situ extraction and fabrication of surface-enhanced Raman scattering substrate (IE-SERS) to perform selective and reliable on-site determination of thiram residue in soil, fruits, and vegetables. In this protocol, the thiram residue on complex surfaces can facilely diffuse into the solvent (dichloromethane (DCM)) and specifically bind to gold nanoparticles (AuNPs), affording the SERS substrate through the embedding of the thiram-trapped AuNPs into the cellulose p-toluenesulfonates (CTSAs) film through the evaporation of DCM. SERS signals of the specifically prepared CTSAs could be used as an internal standard to calibrate the absolute signal of thiram, which can avoid the fluctuation of SERS intensities caused by uneven and irregular morphology of SERS substrate. Thus, reliable quantitation of thiram through SERS detection and superior reproducibility in the SERS measurement (RSD = 4.21%) were achieved. As for directly sensing the thiram residue in soil, the e...

Simultaneous In Situ Extraction and Self-Assembly of Plasmonic Colloidal Gold Superparticles for SERS Detection of Organochlorine Pesticides in Water

Abstract: Rapid component separation and reliable surface-enhanced Raman scattering (SERS) detection of organochlorine pesticide (OCP) residues in real water samples remain major challenges because of sample complexity, trace content, and low molecular affinity for a metal surface. Here, we report a novel strategy of simultaneous in situ extraction and fabrication of plasmonic colloidal gold superparticles (AuSPs) to perform rapid SERS detection of OCPs in environmental water. In this protocol, multiple components of OCPs in complex water were facilely diffused into dichloromethane (DCM) microdroplets and specifically bound to octadecylamine-modified gold nanoparticles (Au-ODAs), affording the SERS substrate through self-assembly of the OCP-trapped Au-ODA into AuSPs with the evaporation of DCM. SERS signals of the specifically prepared Au-ODA could be used as an internal standard to calibrate the absolute signal of OCPs, and multiplex detection could be achieved depending on their molecularly narrow Raman peaks. As for simultaneously sensing four kinds of OCPs (4,4'-DDT, α-endosulfan, tetradifon, and chlordane) in water, the established method showed strong anti-interference ability and comparable quantification ranges with a low limit of detection (LOD). The recoveries ranged from 90.20 to 109.4% for OCPs in farmland, river, and fishpond water, indicating that the established AuSP-based platform is reliable and applicable to the detection of OCPs in real water samples.

“Pomegranate-Like” Plasmonic Nanoreactors with Accessible High-Density Hotspots for in Situ SERS Monitoring of Catalytic Reactions

Abstract: Noble metal nanoparticles (NPs) have enabled surface-enhanced Raman scattering (SERS) for in situ monitoring of NPs-catalyzed reactions. However, it still remains a great challenge to ensure that a...

A Portable Smartphone Platform Using a Ratiometric Fluorescent Paper Strip for Visual Quantitative Sensing.

Abstract: Instrument-free, portable, and direct read-out mini-devices have wider application prospects in various fields, especially for real-time/on-site sensing. Herein, combined with a paper strip, a smartphone sensing platform integrated with a UV lamp and dark cavity by 3D-printing technology has been developed for the rapid, sensitive, instrument-free, and visual quantitative analysis in real-time/on-site conditions. The platform proved the feasibility for visual quantitative detection of pesticide via a fluorescence "on-off-on" response with a single dual-emissive ratiometric paper strip. Red-emitting CdTe quantum dots (rQDs) were embedded into the silica nanoparticles (SiO2 NPs) as an internal reference, while blue-emitting carbon dots (bCDs) as a signal report unit were covalently linked to the outer surface of SiO2 NPs. The blue fluorescence could be quenched by gold nanoparticles (Au NPs) and then recovered with pesticide. The red (R), green (G), and blue (B) channel values of the generated images were determined by a color recognizer application (APP) installed in the smartphone, and the R/B values could be used for pesticide quantification with a sensitive detection limit (LOD) of 59 nM. The smartphone sensing platform based on 3D printing might provide a general strategy for visual quantitative detection in a variety of fields including environments, diagnosis, and safety monitoring.

Advances in flexible surface-enhanced Raman scattering (SERS) substrates for nondestructive food detection: Fundamentals and recent applications

Abstract: Background Food safety has attracted considerable attention in recent years. As a rapid, fingerprint-type recognition and nondestructive detection technique, surface-enhanced Raman scattering (SERS) has been among the promising techniques to meet the increasing needs for food safety analysis. Currently, emerging flexible SERS substrates as an alternative for colloidal and rigid SERS substrates have received great interest. Flexible SERS substrates possess the advantages of easy sampling by wrapping or swabbing on nonplanar surfaces, which facilitate the detection of contaminants from food surfaces and shed new lights on the nondestructive and sensitive detection of food analytes. Scope and approach In this review, the characteristics of different flexible materials such as cellulose, polymer film, cotton fabric, adhesive tape and bio-materials for constructing flexible SERS substrates are introduced, detection strategies including infiltration scheme, swab-sampling and in-situ detection are discussed, and recent applications of flexible SERS substrates in detecting trace pesticides in fruits and vegetables, chemical residues in animal farming including fungicides and antibiotics, illegal food additives and food-borne pathogens are highlighted. Key findings and conclusions Flexible SERS substrates have been increasingly studied for detecting food contaminants. In preparing SERS substrates, different properties of the materials should be considered. For the detection strategies, compared with conventional infiltration scheme, swab-sampling is unique for flexible substrates and can collect target molecules directly from the surface, while in-situ detection is the most convenient, facile and nondestructive. Encouraging application results available show that flexible SERS substrates possess enormous potentials for food safety analysis and surveillance.

Evolving trends in SERS-based techniques for food quality and safety: A review

Abstract: Background Food quality and safety are very important from health as well as fiscal point of view. Surface-enhanced Raman spectroscopy (SERS) techniques have unique advantages in the field of food detection , with characteristics of fast analysis speed, high detection sensitivity, and without interference from the water phase. Scope and approach In this review, recent and potential advances in the application of SERS in food safety and quality from the perspective of SERS substrate and SERS composite systems are addressed. SERS systems such as molecular labeling, immunochromatographic assay, microfluidics, molecularly imprinted polymers, colorimetry and imaging are discussed, and their main advantages and limitations are highlighted. The applications of SERS in food safety are reviewed critically, with focus on the detection of microorganisms, pesticides, metal ions and antibiotics. Furthermore, applications of SERS in food quality regarding food freshness and ingredients are discussed. Key findings and conclusions SERS technology has been widely used in food testing, but it still has shortcomings. In order to establish SERS as a routine tool for the monitoring of food safety and quality, future research should focus on minimizing technical costs, standardizing experimental protocols, developing new SERS substrates, and integrating SERS with other methods to overcome its shortcomings.

Recent Progress in Fast Sample Preparation Techniques.

Abstract: Sample preparation is a critical step in complex sample analysis which effect to sensitivity, selectivity, speed, and accuracy of analytical results. The goal of sample preparation is separation and enrichment. Separation and enrichment are entropy reduction procedures which cannot happen spontaneously. On account of consuming over two thirds of analysis time, sample preparation becomes the bottleneck issue in analytical chemistry. Therefore, fast sample preparation has been received much attention. In this review, a comprehensive survey on progress in fast sample preparation techniques for complex sample in the last 2 years has been composed from more than 180 references. Four approaches for entropy reduction of sample preparation system were generalized, they are energy exchange acceleration, materials-based acceleration, size reduction acceleration, and integration acceleration. Moreover, we highlight the most interesting acceleration techniques, including field-assisted, materials-based rapid mass tra...

Multifunctional cellulose based substrates for SERS smart sensing: Principles, applications and emerging trends for food safety detection

Abstract: Background Food safety issues leading to severe healthy, economic and even social problems and detection of food contaminants has been attracting remarkable attention in recent decades Surface-enhanced Raman scattering (SERS) is one of the most promising techniques to enable detecting contaminants at trace levels Besides, with the emergence of global resource shortages and environmental problems, there is a growing demand for environmentally friendly and renewable resources As a sustainable and biodegradable raw material, cellulose has aroused great interest and stimulated researchers to develop cellulose-based SERS substrates with novel functions Scope and approach The review focuses on the utilizing of cellulosic materials for the design and preparation of various SERS substrates, including cellulose-papers, cellulose fabrics (CFs) and membranes, cellulose nanofibrils (CNFs), bacterial cellulose (BC), nanocrystalline cellulose (NCC), and surface-modified cellulose The applications, challenges and potential solutions of these cellulose-based substrates in food safety detection are also presented, proposed and evaluated Key findings and conclusions For the complexity and diversity of multitudinous food systems, multiple approaches have been successfully employed to manufacture cellulose-based SERS substrates Various types of cellulose with diverse morphology and mechanical properties make them customizable and integratable with multiple technologies in certain realistic applications The explorations of SERS detections displaying excellent performances especially for the complex system/surface analysis with the capability of extraction, swabbing, transferring and concentrating target molecules from complexing food systems The widespread application and prominent performance demonstrating the huge potential for cellulose-based materials to realize commercially viable, sustainable, flexible and green substrates in the near future