AquaSparkTM – Rapid Environmental Monitoring of Listeria monocytogenes

Abstract

In order to prevent microbial contamination of food, monitoring of the production environment, together with the rapid detection of foodborne pathogens have proven to be of utmost importance for Food Safety. Environmental monitoring should detect harmful pathogens at the earliest point in time in order for the necessary interventions to be taken. However, current detection methods fall short with regards to speed, ease of use, and cost. This article aims to present the idea behind NEMIS Technologies, a startup company making use of the novel AquaSparkTM technology for the development of a new generation of bacterial detection methods. These methods utilize chemiluminescence in order to detect live target bacteria in a short period of time compared to that of conventional methods. We show that dry-stressed Listeria monocytogenes can be detected within 24 hours, using small-molecule chemiluminescent probes, together with a bacteria-specific proprietary enrichment broth containing a cocktail of bacteriophages, which enhance the specificity and sensitivity. This novel platform technology has the potential to extend beyond environmental monitoring towards food analyses as well as veterinary and human health.

Next Generation Chemiluminescent Probes for Antimalarial Drug Discovery

“…The concomitant chemiexcitation yields strong luminescence with peak emission between 510 and 550 nm. 35,38 We measured luminescence signals either with a multimode plate reader (unit: counts per second (counts/s)) or an IVIS Spectrum In Vivo Imaging System (unit: photons/ seconds/cm 2 /steradian (p/s/cm 2 /sr); radiance). In absence of β-galactosidase activity, the β-D-galactoside serves as a protective, electron-withdrawing group that keeps the phenoxy-dioxetane molecule in a highly stable and nonluminescent state.…”

“…35,37 Activation of this probe, henceforth called β-gal SENSOR , is initiated by the βgalactosidase-catalyzed removal of a quenching β-D-galactoside substrate. Following the spontaneous elimination of a spacer, the decay of a phenolate intermediate results in the emission of intense green light with an emission maximum at wavelengths between 510 and 550 nm 35,38 (Figure 1). In absence of the βgalactosidase enzyme, the β-gal SENSOR probe remains highly stable, and the enzymatic activation of the probe works in aqueous solutions without the need for other additives such as complex buffer systems or expensive enzymes.…”

“…Furthermore, and in contrast to most luminescence-based systems, the activity of this β-gal SENSOR probe is ATP-independent. Today, phenoxy-dioxetane probes, including the β-gal SENSOR probe, are used for the ultrasensitive detection of bacteria such as Listeria monocytogenes or Salmonella spp.. − …”

Emission Onset Time-Adjustable Chemiluminescent Gold Nanoparticles with Ultrastrong Emission for Smartphone-Based Immunoassay of Severe Acute Respiratory Syndrome Coronavirus 2 Antigen

“…With the advantages of high sensitivity, wide linear range, and simple instrumentation, chemiluminescence (CL) has been widely used in the field of clinical diagnosis, 1,2 food safety assessment, 3,4 environmental monitoring, 5,6 and drug analysis. 7,8 At present, CL assay has become the mainstream technology for in vitro diagnosis.…”

“…With the advantages of high sensitivity, wide linear range, and simple instrumentation, chemiluminescence (CL) has been widely used in the field of clinical diagnosis, , food safety assessment, , environmental monitoring, , and drug analysis. , At present, CL assay has become the mainstream technology for in vitro diagnosis . However, most of the CL systems are flash-type, with light emission appearing immediately upon the addition of coreactant and generally lasting only a few seconds.…”