To be useful in optoelectronic devices and sensors, a platform comprising stable fluorescence materials is essential. Here we constructed quantum dots (QDs) embedded DNA thin films which aims for stable fluorescence through the stabilization of QDs in the high aspect ratio salmon DNA (SDNA) matrix. Also for maximum luminescence, different concentration and configurations of core- and core/alloy/shell-type QDs were embedded within SDNA. The QD-SDNA thin films were constructed by drop-casting and investigated their optoelectronic properties. The infrared, UV-visible and photoluminescence (PL) spectroscopies confirm the embedment of QDs in the SDNA matrix. Absolute PL quantum yield of the QD-SDNA thin film shows the ~70% boost due to SDNA matrix compared to QDs alone in aqueous phase. The linear increase of PL photon counts from few to order of 5 while increasing [QD] reveals the non-aggregation of QDs within SDNA matrix. These systematic studies on the QD structure, absorbance, and concentration- and thickness-dependent optoelectronic characteristics demonstrate the novel properties of the QD-SDNA thin film. Consequently, the SDNA thin films were suggested to utilize for the generalised optical environments, which has the potential as a matrix for light conversion and harvesting nano-bio material as well as for super resolution bioimaging- and biophotonics-based sensors.

Although DNA‐based 2D thin films are easily constructed, 1D fibers and 2D patterns made of DNA are seldom produced due to fabrication complexity. Here, the feasibility of constructing 1D fibers with various diameters and 2D patterns of any shape made of cetyltrimethylammonium chloride (CTMA)‐modified DNA (CDNA, which serves as an ink) via electrospinning and electrohydrodynamic (EHD) jet printing, respectively is demonstrated. The tunable parameters in electrospinning and EHD jet printing systems (e.g., applied bias voltage (V), printing speed (S), and flowrate (F)) are evaluated and the photoluminescence characteristics, UV luminescence photographs, and confocal laser scanning microscope images of the 1D and 2D structures are analyzed. Based on the observations, the fiber diameter decreases as V increases for electrospinning. For EHD, the 1D line widths are inversely proportional to S and V and directly proportional to F. 2D free‐standing mats are also constructed by peeling the mats from the collector after completion of electrospinning. Finally, the QD‐embedded letters of “SKKU” are written on given substrates by an EHD system for verification of pattern drawing. The research gives perspective to construction of CDNA‐based functional scaffolds for bioengineering, stretchable fiber mats for flexible electronics, and direct printing of patterns for microchannel applications.

Although the preparation of DNA thin films with well-defined thicknesses controlled by simple physical parameters is crucial for constructing efficient, stable, and reliable DNAbased optoelectronic devices and sensors, it has not been comprehensively studied yet. Here, we construct DNA and surfactant-modified DNA thin films by drop-casting and spin-coating techniques. The DNA thin films formed with different control parameters, such as dropvolume and spin-speed at given DNA concentrations, exhibit characteristic thickness, surface roughness, surface potential, and absorbance, which are measured by a field emission scanning electron microscope, a surface profilometer, an ellipsometer, an atomic force microscope, a Kelvin probe force microscope, and an UV-visible spectroscope. From the observations, we realized that thickness significantly affects the physical properties of DNA thin films. This comprehensive study of thickness-dependent characteristics of DNA and surfactantmodified DNA thin films provides insight into the choice of fabrication techniques in order for the DNA thin films to have desired physical characteristics in further applications, such as optoelectronic devices and sensors.

Multi-layered DNA and CTMA-modified DNA thin films are fabricated and their novel physical characteristics are investigated.

A simple and hybrid white-light optoelectronic device with a single excitation source with efficient RGB colours on a stable optical platform was demonstrated.