Detection and Quantification of DNA by Fluorophore-Induced Plasmonic Current: A Novel Sensing Approach.

We report on the detection and quantification of aqueous DNA by a fluorophore-induced plasmonic current (FIPC) sensing method. FIPC is a mechanism described by our group in the literature where a fluorophore in close proximity to a plasmonically active metal nanoparticle film (MNF) is able to couple with it, when in an excited state. This coupling produces enhanced fluorescent intensity from the fluorophore-MNF complex, and if conditions are met, a current is generated in the film that is intrinsically linked to the properties of the fluorophore in the complex.

Fluorophore-Induced Plasmonic Current Generation from Copper Nanoparticle Films.

We describe the process of generating a fluorophore-induced plasmonic current (FIPC) from copper nanoparticle films. Previous work and the literature have shown that excited near-field fluorophores are able to plasmonically couple with metal nanoparticle films (MNFs), inducing surface plasmons in the films. These induced surface plasmons are then in turn able to generate a directly measurable electrical current across the film.

Fluorophore-Induced Plasmonic Current Generation from Aluminum Nanoparticle Films.

In this paper we demonstrate fluorophore induced plasmonic current (FIPC) from aluminum nanoparticle films. It has been previously shown that near-field excited fluorophores are able to plasmonically couple with metal nanoparticle films (MNF's) and induce surface plasmons, which in turn leads to a direct measurable electrical current through the MNF. These currents have been detected and quantified in noble metal MNF's, however due to future envisioned cost considerations there has been a push to adapt FIPC for use with less expensive metals.

Sample Preparation and Diagnostic Methods for a Variety of Settings: A Comprehensive Review.

Sample preparation is an essential step for nearly every type of biochemical analysis in use today. Among the most important of these analyses is the diagnosis of diseases, since their treatment may rely greatly on time and, in the case of infectious diseases, containing their spread within a population to prevent outbreaks. To address this, many different methods have been developed for use in the wide variety of settings for which they are needed.

Plasmonic enhancement of nitric oxide generation.

While the utility of reactive oxygen species in photodynamic therapies for both cancer treatments and antimicrobial applications has received much attention, the inherent potential of reactive nitrogen species (RNS) including nitric oxide (NO˙) for these applications should not be overlooked. In recent years, NO˙ donor species with numerous-including photodynamic-mechanisms have been classified with efficacy in antimicrobial and therapeutic applications. While properties of NO˙ delivery may be tuned structurally, herein we describe for the first time a method by which photodynamic NO˙ release is amplified simply by utilizing a plasmonic metal substrate.

Development of a Microplate Platform for High-Throughput Sample Preparation Based on Microwave Metasurfaces.

Sample preparation is one of the most time-consuming steps in diagnostic assays, particularly those involving biological samples. In this paper we report the results of finite-difference time-domain (FDTD) simulations and thermographic imaging experiments carried out with the intent of designing a microplate for rapid, high-throughput sample preparation to aid diagnostic assays. This work is based on devices known as microwave lysing triangles (MLTs) that have been proven capable of rapid sample preparation when irradiated in a standard microwave cavity.

Carbon Nanodots in Photodynamic Antimicrobial Therapy: A Review.

Antibiotic resistance development in bacteria is an ever-increasing global health concern as new resistant strains and/or resistance mechanisms emerge each day, out-pacing the discovery of novel antibiotics. Increasingly, research focuses on alternate techniques, such as antimicrobial photodynamic therapy (APDT) or photocatalytic disinfection, to combat pathogens even before infection occurs. Small molecule "photosensitizers" have been developed to date for this application, using light energy to inflict damage and death on nearby pathogens via the generation of reactive oxygen species (ROS).

The Inverse Relationship between Metal-Enhanced Fluorescence and Fluorophore-Induced Plasmonic Current.

In this work we investigate the relationship between metal-enhanced fluorescence (MEF) and fluorophore-induced plasmonic current (PC). This is accomplished through measurements of both radiative emission (MEF) and direct electrical current generation between discrete metal nanoparticles upon fluorophore excitation (PC). We have conducted these measurements on silver and gold nanoparticle island films, over a range of nanoparticle sizes and spacing in the films.

Fluorophore-Induced Plasmonic Current: Generation-Based Detection of Singlet Oxygen.

In this work, we report the surface-based electrical detection of singlet oxygen using the emerging fluorophore-induced plasmonic current (PC) technique. By this method, we utilize the fluorescent "turn on" response of the well-known singlet oxygen sensor green (SOSG) singlet oxygen (O) fluorescent probe for the generation of fluorophore-induced PC in a silver nanoparticle film. To demonstrate the potential utility of this new technique, a photosensitizing molecule is used to generate O in a solution containing the SOSG probe.

Spectral Distortions in Zinc-based Metal-Enhanced Fluorescence Underpinned by Fast and Slow Electronic Transitions.

Metal-enhanced fluorescence (MEF) is a promising technology with impact in diagnostics, electronics, and sensing. Despite investigation into MEF fundamentals, some properties remain unresearched, notably spectral distortion. To date, publications have described its underpinnings, yet comprehensive analysis is needed, as presented recently for silver films.

Spectral Distortions in Metal-Enhanced Fluorescence: Experimental Evidence for Ultra-Fast and Slow Transitions.

Metal-enhanced fluorescence (MEF) has become an increasingly important technology in recent years, with thorough research addressing the fundamentals of MEF. In many studies, spectral distortion is observed in the enhanced spectra as compared to free-space fluorescence emission profiles. Despite this observation, very little experimentation has been undertaken to investigate the mechanistic underpinnings of spectral distortion in MEF.

Elucidation of a non-thermal mechanism for DNA/RNA fragmentation and protein degradation when using Lyse-It.

Rapid sample preparation is one of the leading bottlenecks to low-cost and efficient sample component detection. To overcome this setback, a technology known as Lyse-It has been developed to rapidly (less than 60 seconds) lyse Gram-positive and-negative bacteria alike, while simultaneously fragmenting DNA/RNA and proteins into tunable sizes. This technology has been used with a variety of organisms, but the underlying mechanism behind how the technology actually works to fragment DNA/RNA and proteins has hitherto been studied.

Low-concentration trypsin detection from a metal-enhanced fluorescence (MEF) platform: Towards the development of ultra-sensitive and rapid detection of proteolytic enzymes.

Proteolytic enzymes, which serve to degrade proteins to their amino acid building blocks, provide a distinct challenge for both diagnostics and biological research fields. Due to their ubiquitous presence in a wide variety of organisms and their involvement in disease, proteases have been identified as biomarkers for various conditions. Additionally, low-levels of proteases may interfere with biological investigation, as contamination with these enzymes can physically alter the protein of interest to researchers, resulting in protein concentration loss or subtler polypeptide clipping that leads to a loss of functionality.

Effects of Lyse-It on endonuclease fragmentation, function and activity.

Nucleases are enzymes that can degrade genomic DNA and RNA that decrease the accuracy of quantitative measures of those nucleic acids. Here, we study conventional heating, standard microwave irradiation, and Lyse-It, a microwave-based lysing technology, for the potential to fragment and inactivate DNA and RNA endonucleases. Lyse-It employs the use of highly focused microwave irradiation to the sample ultimately fragmenting and inactivating RNase A, RNase B, and DNase I.

A comparison of Lyse-It to other cellular sample preparation, bacterial lysing, and DNA fragmentation technologies.

The ability for safe and rapid pathogenic sample transportation and subsequent detection is an increasing challenge throughout the world. Herein, we describe and use bead-beating, vortex, sonication, 903 protein saver cards, and Lyse-It methods, aiming to inactivate Gram-positive and -negative bacteria with subsequent genome DNA (quantitative Polymerase Chain Reaction) qPCR detection. The basic concepts behind the four chosen technologies is their versatility, cost, and ease of use in developed and underdeveloped countries.

Silvered conical-bottom 96-well plates: enhanced low volume detection and the metal-enhanced fluorescence volume/ratio effect.

Many diagnostic fluorescence assays are limited by sensitivity (signal/noise) and minimum sample volume requirements. Herein we report a new, silvered conical-bottom 96-well plate platform used to increase the detectability from very small volumes of micromolar concentrations of fluorophores. This technology employs the principles of metal-enhanced fluorescence (MEF), which is the process by which fluorescence emission is amplified in the near-field of plasmonic nanoparticles.

Heavy carbon nanodots 2: plasmon amplification in Quanta Plate™ wells and the correlation with the synchronous scattering spectrum.

Brominated carbon nanodots are a new carbon nanostructure that exhibits strong phosphorescence without fixation. Herein we report plasmonic amplification of this phosphorescence in silver-coated Quanta Plate™ wells, a technique called metal-enhanced phosphorescence (MEP). Subsequently we correlate the excitation and emission components of brominated carbon nanodots to their respective enhancement values.

Rapid sample preparation with Lyse-It® for Listeria monocytogenes and Vibrio cholerae.

Sample preparation is a leading bottleneck in rapid detection of pathogenic bacteria. Here, we use Lyse-It® for bacterial cellular lysis, genomic DNA fragmentation, and protein release and degradation for both Listeria monocytogenes and Vibrio cholerae. The concept of Lyse-It® employs a conventional microwave and Lyse-It® slides for intensely focused microwave irradiation onto the sample.

Heavy carbon nanodots: a new phosphorescent carbon nanostructure.

Carbon nanodots are nanometer sized fluorescent particles studied for their distinct photoluminescent properties and biocompatibility. Although extensive literature reports the modification and application of carbon nanodot fluorescence, little has been published pertaining to phosphorescence emission from carbon nanodots. The use of phosphors in biological imaging can lead to clearer detection, as the long lifetimes of phosphorescent emission permit off-gated collection that avoids noise from biological autofluorescence.

In Situ Enzymatic Conversion of IMET1 Biomass into Fatty Acid Methyl Esters.

Conventionally, production of methyl ester fuels from microalgae occurs through an energy-intensive two-step chemical extraction and transesterification process. To improve the energy efficiency, we performed in situ enzymatic conversion of whole algae biomass from an oleaginous heterokont microalga IMET1 with the immobilized lipase from . The fatty acid methyl ester yield reached 107.

National Institute of Biomedical Imaging and Bioengineering Point-of-Care Technology Research Network: Advancing Precision Medicine.

To advance the development of point-of-care technology (POCT), the National Institute of Biomedical Imaging and Bioengineering established the POCT Research Network (POCTRN), comprised of Centers that emphasize multidisciplinary partnerships and close facilitation to move technologies from an early stage of development into clinical testing and patient use. This paper describes the POCTRN and the three currently funded Centers as examples of academic-based organizations that support collaborations across disciplines, institutions, and geographic regions to successfully drive innovative solutions from concept to patient care.

Microwave-accelerated method for ultra-rapid extraction of Neisseria gonorrhoeae DNA for downstream detection.

Nucleic acid-based detection of gonorrhea infections typically require a two-step process involving isolation of the nucleic acid, followed by detection of the genomic target often involving polymerase chain reaction (PCR)-based approaches. In an effort to improve on current detection approaches, we have developed a unique two-step microwave-accelerated approach for rapid extraction and detection of Neisseria gonorrhoeae (gonorrhea, GC) DNA. Our approach is based on the use of highly focused microwave radiation to rapidly lyse bacterial cells, release, and subsequently fragment microbial DNA.