Dielectrophoretic Nanoparticle Aggregation for On-Demand Surface Enhanced Raman Spectroscopy Analysis

Abstract

Rapid chemical identification of drugs of abuse in biological fluids such as saliva is of growing interest in healthcare and law enforcement. Accordingly, a label-free detection platform that accepts biological fluid samples is of great practical value. We report a microfluidics-based dielectrophoresis-induced surface enhanced Raman spectroscopy (SERS) device, which is capable of detecting physiologically relevant concentrations of methamphetamine in saliva in under 2 min. In this device, iodide-modified silver nanoparticles are trapped and released on-demand using electrodes integrated in a microfluidic channel. Principal component analysis (PCA) is used to reliably distinguish methamphetamine-positive samples from the negative control samples. Passivation of the electrodes and flow channels minimizes microchannel fouling by nanoparticles, which allows the device to be cleared and reused multiple times.

Carbene modification and reversible crosslinking of silver nanoparticles for controlled antibacterial activity

“…In recent decades, silver nanoparticles (Ag NPs) have been intensively investigated for their unique physical, chemical, and biological properties which underpin applications in various fields, including antibacterial devices 1 – 3 , electric coatings 4 , 5 , sensors 6 , 7 , and catalysts 8 , 9 . It is especially noteworthy that Ag NPs are an important type of broad-spectrum antibacterial materials that show excellent activity against almost all microorganisms; this activity appears to derive from the large surface area which can generate Ag + much faster than bulk silver metal, allowing wide application in medical science 10 – 12 .…”

Rapid and sensitive surface‐enhanced resonance Raman spectroscopy detection for norepinephrine in biofluids

“…Nowadays, surface‐enhanced Raman spectroscopy (SERS) as a kind of rapid analysis method has been widely concerned and applied in neurotransmitters, drug detection, food safety, multicomponent measurement, and plasmon‐enhanced devices . SERS not only can provide the fingerprint information of the analyte molecules but also has the main advantages of less time‐consuming, sensitive, and nondestructive . Moreover, SERS is not affected in water environment because of the weak Raman scattering signal of H 2 O molecule.…”

Strategies for the Development of Metallic‐Nanoparticle‐Based Label‐Free Biosensors and Their Biomedical Applications

“…Salemmilania nd co-workers illustratedt he identification of methamphetamine by using microfluidic chip-based SERS sensing with dielectrophoresis (DEP). [128] DEP was used for the aggregation and liberation of AgNPso nd emandb yp roducing an electric field gradient in microfluidic channels. [129] The microfluidic channel was made of polydimethylsiloxane (PDMS) sandwiched between the electrode substrate and glass cover.…”

“…Salemmilani and co‐workers illustrated the identification of methamphetamine by using microfluidic chip‐based SERS sensing with dielectrophoresis (DEP) . DEP was used for the aggregation and liberation of AgNPs on demand by producing an electric field gradient in microfluidic channels .…”