During stressful conditions, the human body synthesizes catecholamine neurotransmitters such as dopamine and adrenaline, and cortisol. The monitoring of these three molecules levels is crucial for stress management and holds significant medical applications. Here we developed an analytical device that incorporates a biomimetic (tongue-mimic) associated with an optical physico-chemical transducer, able to detect simultaneously cortisol, dopamine and adrenaline in human saliva without pre-treatments, using an array sensor based on fluorescent chemical receptors (BODIPY, Rhodamine, and Naphthylamides) able to interact by non-covalent interaction with cortisol, adrenaline and dopamine, leading to a change of the emission. Calibration, recovery and selectivity have been performed to validate the device. In particular, the linear responses of the array to concentration range of 1 pM-1 mM of the three analytes were demonstrated by PLS analysis, as well as the high selectivity by PLS-DA analysis performed with artificial saliva samples. Analyses in real human saliva samples, compared to the validated analytical methods, demonstrated that our prototype represents the first point-of-care device able to quantify these three analytes in human saliva with one single analysis in a wider concentration range respect to the other standard methods.

The possibility to detect the conservation status of citrus fruit by using an optical array sensor containing synthetic organic fluorescent probes is reported here. Our device shows high sensitivity and selectivity and is of low-cost.

The development of optical probes for formaldehyde detection can lead to the realization of a practical device for its monitoring. This review summarizes formaldehyde sensing by optical sensors.

During a stress condition, the human body synthesizes catecholamine neurotransmitters and specific hormones (called “stress hormones”), the most important of which is cortisol. The monitoring of cortisol levels should be extremely important to control the stress levels, and for this reason, it shows important medical applications. The common analytical methods (HPLC, GC‐MS) cannot be used in real life, due to the bulky size of the instruments and the necessity of specialized personnel. Molecular probes solve these problems due to their fast and easy use. The synthesis of new fluorescent rhodamine probes, able to interact by non‐covalent interactions with cortisol, the recognition properties in solution as well as in solid state by Strip Test, using a smartphone as detector, are here reported. DFT calculations and FT‐IR measurements suggest the formation of supramolecular complexes through hydrogen bonds as main non‐covalent interaction. The present study represents one of the first sensor, based on synthetical chemical receptors, able to detect cortisol in a linear range from 1 mM to 1 pM, based on non‐covalent molecular recognition and paves the way to the realization of practical point‐of‐care device for the monitoring of cortisol in real live.

Fast and easy detection of creatinine in real saliva by an optical array sensor is reported here. The supramolecular approach used in this device leads to high selectivity and sensitivity.

The use of organophosphorus (OP) Nerve Agents (NAs) as chemical weapons still represents a real danger for the safety of population threaten by conflicts or terrorist attacks. A fast and easy-to-use detection of this hazardous gases could make the difference in emergency state. Specifically, the possibility to develop a detection system involving an easily accessible tool, such as a smartphone, is the driving force of the current research work. Due to the great advantages related to the optical sensing, we here report two new BODIPY-based fluorescent receptors for Dimethyl methyl phosphonate (DMMP) NA simulant, with one of the lowest limit of detection. A solid sensor was then developed able to give an OFF/ON response to low ppm concentration of DMMP gas, by using a common smartphone camera with an integrated open-source processing software.