The rapid development of biophotonics and biomedical sciences makes a high demand on photonic structures to be interfaced with biological systems that are capable of manipulating light at small scales for sensitive detection of biological signals and precise imaging of cellular structures. However, conventional photonic structures based on artificial materials (either inorganic or toxic organic) inevitably show incompatibility and invasiveness when interfacing with biological systems. The design of biophotonic probes from the abundant natural materials, particularly biological entities such as virus, cells and tissues, with the capability of multifunctional light manipulation at target sites greatly increases the biocompatibility and minimizes the invasiveness to biological microenvironment. In this review, advances in biophotonic probes for bio-detection and imaging are reviewed. We emphatically and systematically describe biological entities-based photonic probes that offer appropriate optical properties, biocompatibility, and biodegradability with different optical functions from light generation, to light transportation and light modulation. Three representative biophotonic probes, i.e., biological lasers, cell-based biophotonic waveguides and bio-microlenses, are reviewed with applications for bio-detection and imaging. Finally, perspectives on future opportunities and potential improvements of biophotonic probes are also provided.

Microsurgery and biopsies on individual cells in a cellular microenvironment are of great importance to better understand the fundamental cellular processes at subcellular and even single-molecular levels. However, it is still a big challenge for in situ surgery without interfering with neighboring living cells. Here, we report a thermoplasmonics combined optical trapping (TOT) technique for in situ single-cell surgery and intracellular organelle manipulation, without interfering with neighboring cells. A selective single-cell perforation was demonstrated via a localized thermoplasmonic effect, which facilitated further targeted gene delivery. Such a perforation was reversible, and the damaged membrane was capable of being repaired. Remarkably, a targeted extraction and precise manipulation of intracellular organelles were realized via the optical trapping. This TOT technique represents a new way for single-cell microsurgery, gene delivery, and intracellular organelle manipulation, and it provides a new insight for a deeper understanding of cellular processes as well as to reveal underlying causes of diseases associated with organelle malfunctions at a subcellular level.

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Microswarms have shown great potential in biomedical applications at small scales due to their features of wireless actuation and collective microrobotic behaviors. However, actuation of microswarms with strong universality and intelligent biomimetic behaviors is always a great challenge. Here, photothermal damage-free actuation of an intelligent microswarm based on light-induced cold Marangoni flow (CMF) is reported, along with collective drug delivery and targeted cell chemotherapy. This microswarm actuation shows strong universality and high controllability for both abiotic particles and living materials. Importantly, this microswarm exhibits intelligent biomimetic behaviors, such as collective migration, size-based self-organization, and group rejection, due to the synergy between cold flow with individual agents. The distinctive photothermal isolation capability of CMF ensures the microswarm to perform photothermal damage-free biomedical tasks such as collective gene delivery and targeted single-cell chemotherapy. This light-induced CMF provides an optical strategy for photothermal damage-free actuation of intelligent biomimetic microswarm robots, with great promises to perform many collective and cognitive tasks in biomedical applications such as cooperative grasping, collective drug delivery, and precise chemotherapy. IntroductionIn the biological world, many individual organisms, such as honeybees, ants, and herrings, can gather together to form swarms, resulting in hierarchical organizational frameworks. [1] Although individual behaviors are governed by relatively simple rules, the communication and interaction of a vast number of individuals allows swarms to be constructed and assembled into various forms. These swarms exhibit complicated collective behaviors and functions, drastically altering how they interact with their surroundings. [2] Similarly, research on artificial microswarms opens many new possibilities for exploring dynamic interactions

Contamination of nano‐biothreats, such as viruses, mycoplasmas, and pathogenic bacteria, is widespread in cell cultures and greatly threatens many cell‐based bio‐analysis and biomanufacturing. However, non‐invasive trapping and removal of such biothreats during cell culturing, particularly many precious cells, is of great challenge. Here, inspired by the wake‐riding effect, a biocompatible opto‐hydrodynamic diatombot (OHD) based on optical trapping navigated rotational diatom (Phaeodactylum tricornutum Bohlin) for non‐invasive trapping and removal of nano‐biothreats is reported. Combining the opto‐hydrodynamic effect and optical trapping, this rotational OHD enables the trapping of bio‐targets down to sub‐100 nm. Different nano‐biothreats, such as adenoviruses, pathogenic bacteria, and mycoplasmas, are first demonstrated to be effectively trapped and removed by the OHD, without affecting culturing cells including precious cells such as hippocampal neurons. The removal efficiency is greatly enhanced via reconfigurable OHD array construction. Importantly, these OHDs show remarkable antibacterial capability, and further facilitate targeted gene delivery. This OHD serves as a smart micro‐robotic platform for effective trapping and active removal of nano‐biothreats in bio‐microenvironments, and especially for cell culturing of many precious cells, with great promises for benefiting cell‐based bio‐analysis and biomanufacturing.