Unique emissive behavior of combustion-derived particles under illumination with femtosecond pulsed near-infrared laser light

Abstract

Exposure to combustion-derived particles (CDPs), such as carbonaceous particulate matter (PM), has adverse effects on human health. Hence, selective detection of these particles in biological environments is required to understand...

Label-Free Identification of Carbonaceous Particles Using Nonlinear Optical Microscopy

“…The emission spectra of CB show a broadband emission from 380 to 700 nm with the emission intensity increasing at higher emission wavelengths. This is due to the unique WL emission from CB when illuminated using fs-pulsed nIR lasers. , The emission spectra of BrC show different behavior than CB; their response has four main features: (1) a strong third harmonic generation (THG) signal at 435 nm, (2) a weak, broad visible light emission (450–650 nm), (3) a weak second harmonic generation (SHG) signal at 650 nm, and (4) a broad, two-photon excited, autofluorescence (2PAF) signal (>650 nm).…”

“…The capabilities of the setup were tested using CB and the corresponding phasor plot shows that CB has an instantaneous temporal response in line with the expected WL emission (Figure S16). , The weak broad emission from BrC-HA is not instantaneous and the lifetimes indicate that it arises from 3PAF. Similar observations were made for the emission from BrC-HASS, BrC-lignin, and BrC-SRFA.…”

“…Čabanová et al detected amorphous carbon particles from real-life exposure in the mucus and hypertrophic tissue from the human upper respiratory tract using Raman microspectroscopy. , However, Raman microspectroscopy is largely limited by the slow signal acquisition, the sensitivity to fluorescence background (in biomedical samples), and is furthermore challenging for very small particles (<200 nm) . Bové et al have developed a label-free approach to selectively detect BC and CB particles in biological samples based on unique white light (WL) emission using femtosecond (fs) pulsed near-infrared (nIR) laser in a multiphoton microscope. , This technique was used for the detection of CPs in urine and placenta tissue samples, as well as on ivy leaves. − The detection of BC in biological samples based on WL emission is a novel approach; however, it cannot detect BrC nanoparticles (NPs) in biological samples let alone differentiate between BrC and BC.…”

“…31 Bovéet al have developed a label-free approach to selectively detect BC and CB particles in biological samples based on unique white light (WL) emission using femtosecond (fs) pulsed near-infrared (nIR) laser in a multiphoton microscope. 32,33 This technique was used for the detection of CPs in urine and placenta tissue samples, as well as on ivy leaves. 34−37 The detection of BC in biological samples based on WL emission is a novel approach; however, it cannot detect BrC nanoparticles (NPs) in biological samples let alone differentiate between BrC and BC.…”

Label-free detection and size estimation of combustion-derived carbonaceous particles in a microfluidic approach

“…Recently, we have reported that CDCPs can be detected in biological samples based on their unique white light (WL) emission under illumination with femtosecond (fs) pulsed near-infrared (NIR) lasers. 23,24 In this work, we present the development of dual-channel multiphoton flow cytometry (DCMPFC) setup, which combines light scattering with the unique WL emission from individual CDCPs passing through the focal spot of a fs-pulsed NIR laser for their label-free detection, quantification, and size estimation in a sheathed flow. The unique WL emission acts as a specific marker indicating the presence of CDCPs, whereas scattering detection can be used for their size estimation.…”