Effect of Channel Radius on Fluorescent Nanoparticle Based Molecular Communication

The effect of the communication channel size on the transport and subsequent detection of chemical messengers is investigated on millimetric and micrometric channels. The transport of the information carriers, being characterized by an advective and a diffusive contribution, was simulated by varying the flow velocity and the diffusion coefficient. Then, to evaluate the information quality, the Intersymbol Interference (ISI) between two consecutive signals at a specific release delay was estimated. This allowed us to verify that operating under micrometric channel conditions has a larger flow velocity range to obtain completely separated successive signals and smaller release delays can be used between signals. The theoretical results were confirmed by developing a prototype molecular communication platform operating under microfluidic conditions, which enables communication through fluorescent nanoparticles, namely Carbon Quantum Dots (CQDs).

Modular fluorescent nanoparticle DNA probes for detection of peptides and proteins

Fluorescently labeled antibody and aptamer probes are used in biological studies to characterize binding interactions, measure concentrations of analytes, and sort cells. Fluorescent nanoparticle labels offer an excellent alternative to standard fluorescent labeling strategies due to their enhanced brightness, stability and multivalency; however, challenges in functionalization and characterization have impeded their use. This work introduces a straightforward approach for preparation of fluorescent nanoparticle probes using commercially available reagents and common laboratory equipment. Fluorescent polystyrene nanoparticles, Thermo Fisher Scientific FluoSpheres, were used in these proof-of-principle studies. Particle passivation was achieved by covalent attachment of amine-PEG-azide to carboxylated particles, neutralizing the surface charge from − 43 to − 15 mV. A conjugation-annealing handle and DNA aptamer probe were attached to the azide-PEG nanoparticle surface either through reaction of pre-annealed handle and probe or through a stepwise reaction of the nanoparticles with the handle followed by aptamer annealing. Nanoparticles functionalized with DNA aptamers targeting histidine tags and VEGF protein had high affinity (EC50s ranging from 3 to 12 nM) and specificity, and were more stable than conventional labels. This protocol for preparation of nanoparticle probes relies solely on commercially available reagents and common equipment, breaking down the barriers to use nanoparticles in biological experiments.

Modular Fluorescent Nanoparticle DNA Probes for Detection of Peptides and Proteins

Fluorescently labeled antibody and aptamer probes are used in biological studies to characterize binding interactions, measure concentrations of analytes, and sort cells. Fluorescent nanoparticle labels offer an excellent alternative to standard fluorescent labeling strategies due to their enhanced brightness, stability and multivalency; however, challenges in functionalization and characterization have impeded their use. This work introduces a straightforward approach for preparation of fluorescent nanoparticle probes using commercially available reagents and common laboratory equipment. Fluorescent polystyrene nanoparticles, Thermo Fisher FluoSpheres™, were used in proof-of-principle studies. Particle passivation was achieved by covalent attachment of amine-PEG-azide to carboxylated particles, neutralizing the surface charge from -47 to -17 mV. A conjugation-annealing handle and DNA aptamer probe was attached to the azide-PEG nanoparticle surface either through reaction of pre-annealed handle and probe or through a stepwise reaction of the nanoparticles with the handle followed by aptamer annealing. Nanoparticles functionalized with DNA aptamers targeting histidine tags and VEGF protein had high affinity (EC50s ranging from 2-7 nM) and specificity, and were more stable than conventional labels. This protocol for preparation of nanoparticle probes relies solely on commercially available reagents and common equipment, breaking down the barriers to use of nanoparticles in biological experiments.

Fluorescence NanoParticle Detection in a liquid sample using the Smartphone for Biomedical application

In the present work, a Smartphone-based Fluorescence Nanoparticle Detector (SPF-NPD) was developed. This method is intended for use in the identification of biological agents in biomedical applications. Here, an android application-based algorithm was developed to analyze the fluorescent nanoparticle intensity level in a target sample. The setup consists of an LED light source, an Eppendorf tube holder, and a smartphone to acquire the fluorescent intensity level in the sample to enable the detection of pathogens within few seconds. High-resolution cameras available on recent smartphones have made live detection more accurate and convenient for healthcare applications. The concept of fluorescent nanoparticle detection with a smartphone has led to a portable device and having potential application in healthcare. In this proposed method the intensity level is analyzed with 5 pixels algorithm, the center pixel followed by four immediate neighbours’ pixels which can analyze with minimal sample quantity. Also, the robustness of the developed algorithm was verified with various megapixel camera ranges from 8 MP to 20 MP.

One-step synthesis of M13 phage-based nanoparticles and their fluorescence properties

M13 bacteriophage is an attractive alternative source for fluorescent nanoparticle synthesis.

Efficient NIR-I fluorescence photoswitching based on a giant fluorescence quenching in photochromic nanoparticles

A photoswitchable near-infrared (NIR) fluorescent nanoparticle (NP) was designed and prepared. The NP showed a characteristic AIE property and a high-contrast NIR fluorescence photoswitching with full reversibility. Such efficient NIR...

Including fluorescent nanoparticle probes within injectable gels for remote strain measurements and discrimination between compression and tension

Remote measurement of the deformation ratio and discrimination between tension and compression for injectable gels is demonstrated using photoluminescence and two types of fluorescent probe particles.