Efficient Fluorescence Resonance Energy Transfer between Quantum Dots and Gold Nanoparticles Based on Porous Silicon Photonic Crystal for DNA Detection

Abstract

A novel assembled biosensor was prepared for detecting 16S rRNA, a small-size persistent specific for Actinobacteria. The mechanism of the porous silicon (PS) photonic crystal biosensor is based on the fluorescence resonance energy transfer (FRET) between quantum dots (QDs) and gold nanoparticles (AuNPs) through DNA hybridization, where QDs act as an emission donor and AuNPs serve as a fluorescence quencher. Results showed that the photoluminescence (PL) intensity of PS photonic crystal was drastically increased when the QDs-conjugated probe DNA was adhered to the PS layer by surface modification using a standard cross-link chemistry method. The PL intensity of QDs was decreased when the addition of AuNPs-conjugated complementary 16S rRNA was dropped onto QDs-conjugated PS. Based on the analysis of different target DNA concentration, it was found that the decrease of the PL intensity showed a good linear relationship with complementary DNA concentration in a range from 0.25 to 10 μM, and the detection limit was 328.7 nM. Such an optical FRET biosensor functions on PS-based photonic crystal for DNA detection that differs from the traditional FRET, which is used only in liquid. This method will benefit the development of a new optical FRET label-free biosensor on Si substrate and has great potential in biochips based on integrated optical devices.

Highly Selective Detection of Metronidazole by Self-Assembly via 0D/2D N–C QDs/g-C3N4 Nanocomposites Through FRET Mechanism

“…6c)). The FRET efficiency increased from 5.3 to 36.55% [29]. This result suggests that the quenching mechanism is sufficiently able to detect MNZ through the oxygen atom in MNZ that destroys the hydrogen bond between carbon quantum dots and carboxylated carbon nitride through competition, thereby destroying the FRET between N-C QDs and g-C 3 N 4 nanosheets.…”

Detection of Ammonia-Oxidizing Bacteria (AOB) Using a Porous Silicon Optical Biosensor Based on a Multilayered Double Bragg Mirror Structure

“…The resolution of the grid in the calculated reflectance spectrum was set to be 1 nm. Following our earlier work, the refractive indices were determined by experiment to be n L1 = n L2 = 1.4 and n H1 = n H2 = 2.0, respectively, and the layer thickness related to the reflective indexes were d = λc/(4n) by Bruggemann’s effective medium theory [ 11 , 14 , 17 ].…”

“…Figure 2 a,b, we used transfer matrix method by Matlab software to calculate reflectance spectra of the Bragg mirror of (n L n H ) 9 , (n L n H ) 10 , (n L n H ) 11 , and (n L n H ) 12 sequences with resonance wavelengths at 1110 nm and 1530 nm, respectively. The transfer matrix method can be found in more detail in [ 11 , 14 , 17 ]. We can observe a high reflectivity stop at 1110 nm and 1530 nm with interference fringes in the reflectance spectrum.…”

“…The fabrication of one-dimensional photonic crystal of PS can be referenced from our early works [ 11 , 14 , 17 ]. In this experiment, PS layers have been produced with highly p-type silicon ( ρ = 0.01–0.06 Ω·cm) with an exposing area of approximately 0.785 cm 2 by electrochemical etching at room temperature (RT).…”

“…Many researchers have investigated various aspects of PS, such as morphological, optical, and electrical properties, especially in structural properties based on the preparation of integrated optical devices [ 8 , 9 , 10 ]. Currently, photonic crystal structures are widely used as transducers for optical sensing applications based on controlling the refractive index of the PS layers and the change in the effective refractive index due to biomolecule attachment events [ 11 , 12 ]. The dielectric functions of periodically-modulated photonic crystals results in light propagation dramatically different from the bulk materials, such as waveguides, Bragg mirrors, rugate filters, and Fabry-Perot filters [ 13 , 14 ].…”