Sunlight utilization by plants via the photosynthesis process is limited to the visible spectral range. How to expand the utilization spectral range via construction of a hybrid photosynthetic system is a hot topic in this field. In this work, far-red carbon dots (FR-CDs) with excellent water solubility, good biocompatibility, high quantum yield (QY), and superior stability were prepared by a one-step microwave synthesis in 3 min. The as-prepared FR-CDs is an efficient converter transferring ultraviolet A (UV-A) light to 625-800 nm far-red emission, which can be directly absorbed and utilized by chloroplasts. Due to the broader spectral utilization of solar energy and Emerson effect, increased photosynthetic activity can be achieved both in vivo and in vitro when applied for Roman lettuce. The in vitro hybrid photosynthetic system via coating chloroplasts with FR-CDs presents higher electron transfer efficiency between PS II (photosystem II) to PS I (photosystem I), which consequently increases the ATP production. The in vivo experiment further confirms that FR-CDs-treated lettuce can induce a 28.00% higher electron transfer rate compared with the control group, which results in 51.14 and 24.60% enhancement of fresh and dry weights, respectively. This work is expected to provide a way for improving the conversion efficiency from solar energy to chemical energy. (PS II) to photosystem I (PS I), which consequently increases the ATP production. The in vivo experiment further confirms that FR-CDs-treated lettuce can induce a 28.00% higher electron transfer rate compared with the control group, which results in 51.14 and 24.60% enhancement of fresh and dry weights, respectively. This work is expected to provide a way for improving the conversion efficiency from solar energy to chemical energy.
Keywords: Roman lettuce; chloroplasts; far-red carbon dots; light-harvesting; photosynthesis.