Paper-based fluorescence devices, with smartphone aids, bring considerable operation convenience for tetracycline (TC) sensing. Nevertheless, they must meet the challenge in real determination against complicated backgrounds. Considering that, we present a programmable-printing paper-based device and then apply it to TC determination for various natural samples. MoS2 NPs and Gmp/Eu-Cit are synthetized as composite probes. A static quenching process is found with MoS2 NP fluorescence at 430 nm, while significant magnification of Gmp/Eu-Cit emission is obtained at 617 nm, establishing a valuable ratiometric indicator. Remarkably, two-stage programmable printing maximizes the proposed sensing capability. A transitive device, containing a gradually changing amount of a certain probe, is prepared to sense TC. With a homemade smartphone application and 3D-printed measurement chamber, the corresponding signals are examined to explore optimal setups. These setups are automatically processed to prepare the final-version device, not requiring manual operations. Benefitting from this interesting feature, the proposed device gains many rewards in performances. It effectively senses TC in a wide range from 12.7 nM to 80 μM and simultaneously provides naked eye-legible signals and smartphone-based readouts with confident selectivity and stability. This device is consequently applied for various samples of soil, river water, milk, and serum and meets well with HPLC–MS and recovery tests.

This study was conducted to assess the effects of boiling, steaming, and oven-cooking on the fatty acid profile, physicochemical composition, and sensory properties of Atlantic salmon fish. The protein content of steamed (18.90%) and oven-cooked (20.59%) salmon was significantly higher than that of boiled (16.69%) and raw fish (14.73%). Analysis of the fatty acids profile revealed that steaming significantly ( p < 0.05 ) influenced the fatty acid contents of Atlantic salmon by recording the lowest SFA and the highest omega-3, omega-6, and PUFA contents. Textural properties such as hardness, gumminess, and chewiness were significantly higher ( p < 0.05 ) in oven-cooked salmon, with steamed salmon having significantly lower and higher values of hardness (75.32 ± 4.73) and springiness (90.56 ± 3.94), respectively. Also, volatile organic compounds, including aldehydes, ketones, and alcohol, were significantly higher ( p < 0.05 ) in oven-cooked and steamed salmon. Additionally, the E-nose sensors analysis showed that S2 and S7 were significantly correlated during oven-cooking and steaming. Furthermore, low-field NMR analysis showed that the values of T21 and T22 relaxation characteristics of raw and cooked samples fluctuated, with steamed salmon having the highest peak values indicating reduced proton mobility and increased freedom of the protons compared to other treatments. Therefore, steaming resulted in the best quality salmon when considering the fatty acid profile, physicochemical composition, and sensory properties of Atlantic salmon fish, suggesting further studies to ascertain its effectiveness compared to modern treatments.

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