Dual-mode fluorescence and electrochemiluminescence sensors based on Ru-MOF nanosheets for sensitive detection of apoE genes.

A fluorescence-electrochemiluminescence (FL-ECL) dual-mode sensor for apoE gene detection has been developed, leveraging the unique properties of ruthenium metal organic framework nanosheets (RuMOFNSs). The system utilizes the quenching effect of the Ru(bpy)32+ ECL signal by ferrocene, leading to the synthesis of a multi-electron electrical signal marker, bisferrocene. By immobilizing the P-DNA on RuMOFNSs, bisferrocene quenches both FL and ECL signals. The addition of T-DNA and the consequent formation of double-stranded DNA enable the ExoIII enzyme to excise the bisferrocene fragment, restoring the signals. The sensor demonstrates wide detection linear ranges (1 fM to 1 nM for FL and 0.01 fM to 10 pM for ECL) and remarkable sensitivity (0.048 fM for FL and 0.016 fM for ECL). The dual-mode design offers enhanced reliability through a self-correction feature, reducing false positives. Compared to single-mode sensors, the dual-mode sensor shows significant advantages. Real-world testing confirms the sensor's capacity for robust detection in actual samples, underscoring its promising application in early disease diagnosis. This innovative approach opens up avenues for multi-signal response sensors, offering significant potential for diagnostic technologies.

A novel fluorescent sensor with an overtone peak reference for highly sensitive detection of mercury (II) ions and hydrogen sulfide: Mechanisms and applications in environmental monitoring and bioanalysis.

The present study introduces a novel fluorescent sensor with an overtone peak reference designed for the detection of mercury (Ⅱ) ions (Hg2+) and hydrogen sulfide (H2S). The study proposes two novel response mechanisms that hinges on the synergistic effect of cation exchange dissociation (CED) and photo-induced electron transfer (PET). This sensor exhibits a remarkable detection limit of 2.9 nM for Hg2+. Additionally, the sensor reacts with H2S to generate nickel sulfide (NiS) semiconductor nanoparticles, which amplify the fluorescence signal and enable a detection limit of 3.1 nM for H2S. The detection limit for H2S is further improved to 29.1 pM through the surface functionalization of the nanomaterial with pyridine groups (increasing reactivity) and chelation of gold nanoparticles (AuNPs), which enhances the sensor's specificity. This improvement is primarily due to the surface plasmon resonance (SPR) of AuNPs and their affinity for H2S. The single-emission strategy can yield skewed results due to environmental changes, whereas the overtone peak reference strategy enhances result accuracy and reliability by detecting environmental interference through reference emission peaks. In another observation, the low-toxicity dihydropyrene-bipyridine nanorods (TPP-BPY) has been successfully utilized for both endogenous and exogenous H2S detection in vivo using a mouse model. The successful development of TPP-BPY is expected to provide an effective tool for studying the role of H2S in biomedical systems.