## 1 Introduction  
Control of blood glucose levels is extremely important for patients with diabetes [1, 2, 3, 4]. However, unpredictable fluctuations in blood glucose levels and variations between individual patients make it difficult to effectively treat diabetes [5, 6]. Particularly, special care is required for insulin-dependent diabetes patients because insulin injection can sometimes result in hypoglycemia, leading to coma or death. Therefore, continuous glucose monitoring (CGM) is recommended for such patients. Four CGM systems are available on the market [7]. Most of these systems are enzyme-immobilized needle-injection systems. The high maintenance cost and inconvenience of replacing the sensors every 6-14 days is the main hurdle for their widespread use [8]. Globally, a very low percentage of patients with diabetes who require CGM use the systems worldwide [9]. While there have been great efforts to increase the instability of enzymes, the period of use of the enzymatic CGM systems has been not increased for a long time [10, 11]. The one non-enzymatic CGMsystem relies on a diboronic acid-based fluorescent molecule. For the specific and reversible interaction of diboronic acids with glucose, several derivatives have allowed in vivo glucose monitoring [12; 13; 14; 15; 16; 17]. The immune response to the implanted device generates reactive oxygen species (ROS) such as H\({}_{2}\)O\({}_{2}\)[18]. Therefore, resistance to ROS is highly important for the long-term use of CGM. The addition of an electron acceptor group to the aromatic moieties with boronate residues increased the resistance to oxidation by ROS [19]. For example, trifluoromethyl-substituted dibornic acid anthracene resulted in a 24-fold increase in the half-life for 10 uM of H\({}_{2}\)O\({}_{2}\)[20]. Additionally, the fluorescent probe under the skin can be protected against reactive oxygen species (ROS) by a platinum coating. As the result, the non-enzymatic implantable system can be used for up to 180 days [13]. However, the excitation and emission spectrum of the dye are largely overlapped. The maximum excitation and emission wavelengths of the used trifluoromethyl derivative were approximately 405 nm and 430 nm, respectively. The largely overlapped spectra and the small Stokes shift make it difficult to select a light source and detector pair. To minimize the noise resulting from the overlapped spectra, the system needs to use a higher excitation energy source than the dye's maximum excitation and an additional photodiode as a reference, aside from the main one [21]. The lower excitation wavelength can result in more heat generation and energy consumption. Therefore, improvement of the optical characteristics, such as a large Stokes shift and longer excitation wavelength, is still in demand. In this study, we report the synthesis of a new diboronic anthracene with a larger Stokes shift and longer excitation wavelength than the commercially used analog. It is known that the acetyl group can increase the emission wavelength of the dye [22; 23]. By introducing the acetyl group on the anthracene, we could increase the Stokes shift up to 90 nm. The introduced acetyl group did not affect the resistance to ROS. Instead, the acetylation resulted in an improved glucose detecting ability for the dye.