The work carried out until M18 was related to the (i) engineering of the active/passive constituent components of the optoplasmonic chip -OPM (i.e OLEDs, OPD, optical filter and nanoplasmonic grating - NPG) and the realization of the single-component prototypes and (ii) design, development and testing of the multiplex assays at the basis of the biorecognition at the NPG surface and of the capture/release at the microsieve membrane.
In particular, the demonstration of the working of the sensing module was reported by CNR and PLASM in WP2 (Integrated system for optoplasmonic sensing) by measuring the signal inputs/outputs of the single-components. In the case of the photonic module comprised by OLED, OPD and optical filter the interaction of the single components into an integrated configuration of the module was demonstrated. Moreover, the effectiveness of the signal enhancement of PEF detection was estimated in lab conditions which allowed the identification of a resonated risk assessment of the dual detection-modality approach.
The continuous collaboration among WFSR, INN and PLASM aimed at defining and implementing a shared and exhaustive action plan for determining the most effective and reliable approaches in the multiplex biorecognition of analytes (i.e. aptamer- vs antibody-based assays in the case of heavy-metal detection) and in biofunctionalization of both the NPG and microsieve membrane surfaces. The most relevant output of the general overview is the identification of the need of an amplification step of microbial DNA in the detection of microbes localized at the microsieve membrane of the sensor.
A risk management activity was dedicated to the identification and solving of the possible issues related to (i) the integration of the single components into the different modules of the sensor, and (ii) the optimization of the different treatment affecting the processing of the target compounds (i.e. thermal treatment, surface biofunctionalization, DNA amplification,…).
From M18 to the end of the project (extended end at M42) we established the potentiality of h-ALO sensor technologies to ensure quality and safety across different food chains, by demonstrating the applicability of the multiple modules of the sensor in real settings. We tested real samples belonging to matrices as model systems, such as skimmed milk, aquaponic water, and craft beer. Each sample was chosen for its relevance to specific contaminants, namely Albendazole in milk, Cadmium and E. Coli in aquaponic water, and Lactobacillus in beer.
We highlight that the overall usability of the h-ALO instrument comprised by the reagent and sensor cartridges is guaranteed by all the sample matrices ought to be filtered by using a single microsieve membrane in the reagent cartridge where microbes are retained on the membrane while pesticides and heavy metals run through. Heavy metals and pesticides are transported directly into the sensing module in the sensor cartridge for SPR detection, while the microbes are processed for nucleic acids extraction, collection and amplification. After amplification, real-time detection of double stranded DNA is performed in the amplification chamber.
Multiple protocols of use and guidelines such as the ones correlated to preparation of the samples from different food matrices to be used in the sensor, the use of sensor for generating data, management of the data generated by the sensor were discussed, optimized and shared with the End-users Committee.
