Oxygen‐derived free radicals: Production, biological importance, bioimaging, and analytical detection with responsive luminescent nanoprobes

Abstract

Oxygen-derived free radicals (ODFRs) are partially reduced oxygen reactive intermediates in living organisms during various biological processes, such as mitochondrial respirations, enzyme-catalyzed oxidations, and radiolysis. Of various ODFRs being identified, superoxide anion (O 2•-) and hydroxyl (•OH) radicals are extensively investigated. Due to their high reactivity, these radicals can oxidize many biomolecules, including nucleic acids, proteins, lipids, and carbohydrates, which would damage some key cellular components. Under oxidative stress, elevated oxygen radical levels are closely associated with various diseases, such as neurodegenerative diseases, cardiovascular diseases, rheumatoid arthritis, and cancers. In this context, a number of responsive nanoprobes have been developed for luminescent detection of ODFRs in living organisms.In this review, we briefly introduce the production of ODFRs and their biological importance for various diseases. We then extensively summarize responsive nanoprobes for detection and bioimaging of these two oxygen radicals, O 2 •and•OH, which are designed and developed based on their specific oxidation mechanisms in the recent decade. Challenges and some future research directions are also proposed as the conclusion. K E Y W O R D Sluminescence biosensing and imaging, oxygen-derived free radical, radical-associated diseases, responsive nanoprobes, superoxide anion and hydroxyl radical 1This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Determination and Imaging of Small Biomolecules and Ions Using Ruthenium(II) Complex-Based Chemosensors

“…These biomolecules play very important roles in biological systems [25,27,161]. For example, ROS/RNS are important signaling molecules in the body, while high levels of ROS/RNS lead to oxidative stress, causing damage to the cell membrane, protein and nucleic acids [162]. It has been reported that the overexpression of ROS/RNS is implicated in pathological processes in inflammation, cancer, cardiovascular disease, Alzheimer's disease (AD) and aging [162,163].…”

“…For example, ROS/RNS are important signaling molecules in the body, while high levels of ROS/RNS lead to oxidative stress, causing damage to the cell membrane, protein and nucleic acids [162]. It has been reported that the overexpression of ROS/RNS is implicated in pathological processes in inflammation, cancer, cardiovascular disease, Alzheimer's disease (AD) and aging [162,163]. Nevertheless, determination and monitoring their levels in situ remain a challenge due to (1) the limited numbers of robust chemosensors and (2) their high reactivity and the short lifetime of Fig.…”

“…ROS is a group of reactive biomolecules and free radicals derived from molecular oxygen [162,164,179]. Generally, ROS include O 2 •− , hydroxyl radicals (•OH), hydrogen peroxide (H 2 O 2 ), singlet oxygen ( 1 O 2 ) and hypochlorous acid (HOCl) [164].…”

“…Generally, ROS include O 2 •− , hydroxyl radicals (•OH), hydrogen peroxide (H 2 O 2 ), singlet oxygen ( 1 O 2 ) and hypochlorous acid (HOCl) [164]. These short-lived species display high reactivity, causing oxidation of other biomolecules, such as DNA, lipids and proteins [162]. In the past years, a number of Ru(II) complex chemosensors have been developed for the detection and imaging of 1 O 2 and HOCl [180], which will be discussed in this section.…”

Luminescent Zn (II)-Based Nanoprobes: A Highly Symmetric Supramolecular Platform for Sensing of Biological Targets and Living Cell Imaging

“…On the other hand, the easy-tooperate PL signal guarantee a low expansive, real-time, in situ analysis. Finally, the mimic behavior of the nanoprobes into the living cell benefits from the non-invasiveness proper of the biomolecules (Liu et al, 2021). As will be discussed in the next section, the tailored composition of nanosized hybrid probes can represent a value-added in the design of the new generation of PL smart tools.…”