Gold Nanoplate‐Enhanced Chemiluminescence and Macromolecular Shielding for Rapid Microbial Diagnostics

Abstract

With the global rise of antimicrobial resistance, rapid screening and identification of low concentrations of microorganisms in less than 1 h becomes an urgent technological need for evidence-based antibiotic therapy. Although many commercially available techniques are labeled for rapid microbial detection, they often require 24-48 h of cell enrichment to reach detectable levels. Here, it is shown that the widely used reducing agent tris(2-carboxyethyl)phosphine (TCEP) can also act as a powerful oxidant on gold nanoplates and subsequently lead to a strong catalysis of luminol chemiluminescence. The catalytic reaction results in up to 100-fold signal enhancement and unprecedented stable luminescence for up to 10 min. However, when TCEP is exposed to microorganisms, it is oxidized by the microbial surface proteins and loses its catalytic properties, leading to a decrease in chemiluminescence. The competitive interaction of TCEP with Au nanoplates and microorganisms is used to introduce a homogenous rapid detection method that allows microbial screening in less than 10 min with a limit of detection down to 100 cfu mL . Furthermore, the concept of microbial macromolecular shielding using antibody-conjugated polymers is introduced. The combination of TCEP redox activity and macromolecular shielding enables specific microbial identification within 1 h, without preconcentration, cell enrichment, or heavy equipment other than a hand-held luminometer. The technique is demonstrated by specific detection of methicillin-resistant Staphylococcus aureus in environmental and urine samples containing a mixture of microorganisms.

Ultrasensitive haptoglobin biomarker detection based on amplified chemiluminescence of magnetite nanoparticles

“…Chemiluminescence (CL) is a practical opto-chemical approach for designing real-life sensing applications, e.g., safety control within food and pharmaceutical industries, environmental hazardous contaminants monitoring and clinical examination, using the discharged radiation for high sensitivity analysis of the target molecule [13][14][15][16][17][18]. The addition of superparamagnetism characteristics onto CL bioassays in means of magnetic nanoparticles (MNPs), alleviate the high-throughput immunoassay protocols by convenient separation, widespread the linear sensing range, enhance the reaction kinetics and encompass high surface area for collected biomolecular recognition [19].…”

Gold Nanoparticle Size-Dependent Enhanced Chemiluminescence for Ultra-Sensitive Haptoglobin Biomarker Detection

“…Chemiluminescence (CL) is widely applied chemically driven electromagnetic radiation for real-life applications, from clinical monitoring, food and pharmaceutical safety control, and up to trace levels of environmental pollutants analysis, utilizing its high sensitivity toward the assessment of the limiting target reactant involved in the luminol reaction [1,2,3,4,5,6,7,8,9,10,11]. The low emitted radiation within complex samples such as blood, milk, urine, or biological tissues, can be efficiently augmented by the addition of a catalyst, e.g., metal or semiconductor nanoparticles, catalytic ions, enzymes, into the luminol CL system.…”

“…Gold nanoparticles (GNPs) are one of the most frequently used nanoparticles for analytical applications harnessing the ease of opto-electronic property fine-tuning by mild changes in the nanoparticles size, morphology, surface functionality, and local environment [12,13]. Indeed, numerous case studies and reports employed GNPs for enhanced CL (eCL) presenting a repertoire of novel ultrasensitive bioassays [4,5,6,12,13,14,15,16,17,18,19]. Singh et al have reported the use of sequence-specific single-stranded DNA probes anchored on the exterior of GNPs surface for the hybridization with the complementary DNA target regions of Ceratocystis fagacearum [15].…”

“…The bio-platform can be adapted for the design of upgraded biosensing devices, designing novel lab-on-a-chip architectures, and nano-fluidic schemes. Bui et al have reported on a competitive CL detection assay based on tris(2-carboxyethyl)phosphine (reducing agent) interaction with both microorganisms and GNPs, which was used for rapid microbial screening and identification in less than 10 min, while presenting a LOD as low as 100 cfu mL −1 and a proportional response up until 10 7 cfu mL −1 [4]. Moreover, the concept was demonstrated for real-life samples in less than 1 h through the specific identification of methicillin-resistant Staphylococcus aureus in urine and environmental samples enclosing a complex mixture of bacteria.…”

Ultrasensitive Chemiluminescence Biosensor for Nuclease and Bacterial Determination Based on Hemin-Encapsulated Mesoporous Silica Nanoparticles

“…Comparatively, chemiluminescence (CL) relies on illumination produced by chemical reactions of trace analysts, which can be exempted from the excitation light source and therefore avoid interference from light scattering . As a result, CL possesses simple instrumentation and operation, wide calibration ranges, and suitability for miniaturization, , offering a great potential for the determination of pathogenic microorganisms . Classically, luminol-based CL reaction coupling of hydrogen peroxide (H 2 O 2 ) and other oxidations is the main illuminated medium because of its inexpensiveness and high sensibility.…”