Portable SERS-enabled Micropipettes for Microarea Sampling and Reliably Quantitative Detection of Surface Organic Residues

Abstract

We report the first microsampling device for reliably quantitative, label-free and separation-free detection of multicomponents of surface organic residues (SORs) by means of a quality controllable surface-enhanced Raman scattering (SERS)-enabled micropipette. The micropipette is comprised of a drawn glass capillary with a tiny orifice (∼50 μm) at the distal tip, where the specially designed nanorattles (NRs) are compactly coated on the inner wall surface. SERS signals of 4-mercapto benzoic acid (MBA) anchored inside the internal gap of NRs could be used to evaluate and control the quality of micropipettes and, therefore, allow us to overcome the limitations of a reliably quantitative SERS assay using traditional substrates without an internal standard. By dropping a trace extraction agent on targeting SORs located on a narrow surface, the capillary and SERS functionalities of these micropipettes allow on-site microsampling via capillary action and subsequent multiplex distinction/detection due to their molecularly narrow Raman peaks. For example, 8 nM thiram (TMTD), 8 nM malachite green (MG), and 1.5 μM (400 ppb) methyl parathion (MPT) on pepper and cucumber peels have been simultaneously detected in a wide detection range. The portable SERS-enabled device could potentially be facilely incorporated with liquid-liquid or solid phase micro-extracting devices for a broader range of applications in rapid and field analysis of food/public/environment security related SORs.

Plasmonic Nanoassemblies: Tentacles Beat Satellites for Boosting Broadband NIR Plasmon Coupling Providing a Novel Candidate for SERS and Photothermal Therapy

“…When comparing this with popular SERS tags like rhodamine 6G (R6G), reports suggest experimental LOD of 10 −6 m with nanostructured Ag−Au bimetallic surfaces . Another example reporting a complicated gold−SERS label−silver nanorattle structure deposited as films inside micropipettes for SERS detection of methyl parathion featured experimental LOD of 10 −6 m and calculated a theoretical LOD (from calibration curves) to be 68 × 10 −9 m (6.8 × 10 −8 m ) . A recent review suggests that most designed nanostructures allow detection of medium‐high Raman cross‐section molecules (labels) in the concentration range of 10 −5 to 10 −7 m , and detection of signal below that is quite challenging.…”

Catalytic Chemosensing Assay for Selective Detection of Methyl Parathion Organophosphate Pesticide

“…These inhibitory and accumulation processes imperil human health by contraction of the pupils, profuse salivation, convulsions, involuntary urination and defecation, and even death by asphyxiation . Methods for detecting methyl parathion typically employ analytical techniques such as mass spectrometry, molecular imprinting of polymers, electrochemical detection, and enzyme immunoassays . However, these analytical methods usually suffer from extensive analytical processing, laborious synthetic procedures, a lack of specificity, and expensive instrumentation.…”

“…[37][38][39] Methods for detecting methyl parathion typically employ analytical techniquess uch as mass spectrometry,m olecular imprinting of polymers, electrochemical detection, and enzyme immunoassays. [40][41][42][43][44] However, these analytical methods usually suffer from extensive analyticalp rocessing, laborious synthetic procedures,alack of specificity,a nd expensive instrumentation.A lthoughc hemosensorsh ave also been developed for detecting methylp arathion, the main hindrance in the path of their development is the interference from other structurally similar aromatic phosphate esters. [45][46][47][48][49][50]…”

Fabrication of flexible paper‐based Surface‐enhanced Raman scattering substrate from Au nanocubes monolayer for trace detection of crystal violet on shell

“…At the same time, filter paper has a very powerful sample extraction and filtration function. On the basis of excellent liquid conductivity and softness, various detection modes have been proposed, such as wiping type, lateral flow, and longitudinal flow . For instance, White et al proposed a low cost and easy device using a novel vertical flow membrance system with inkjet‐printed technique .…”