Modular 3D-printed fluorometer/photometer for determination of iron(ii), caffeine, and ciprofloxacin in pharmaceutical samples

Abstract

The demand for the development of portable and low-cost analytical devices has encouraged studies employing additive manufacturing techniques, such as 3D-printing. This method can be used to produce components such as printed electrodes, photometers, and fluorometers for low-cost systems that provide advantages including low sample volume, reduced chemical waste, and easy coupling with LED-based optics and other instrumental devices. In the present work, a modular 3D-printed fluorometer/photometer was designed and applied for the determination of caffeine (CAF), ciprofloxacin (CIP), and Fe(II) in pharmaceutical samples. All the plastic parts were printed separately by a 3D printer, using Tritan as the plastic material (black color). The final size of the modular 3D-printed device was 12 × 8 cm. The radiation sources were light-emitting diodes (LEDs), while a light dependent resistor (LDR) was used as a photodetector. The analytical curves obtained for the device were: y = 3.00 × 10⁻⁴ [CAF] + 1.00 and R² = 0.987 for caffeine; y = 6.90 × 10⁻³ [CIP] − 3.39 × 10⁻² and R² = 0.991 for ciprofloxacin; and y = 1.12 × 10⁻¹ [Fe(II)] + 1.26 × 10⁻² and R² = 0.998 for iron(II). The results obtained using the developed device were compared with reference methods, with no statistically significant differences observed. The 3D-printed device was composed of moveable parts, providing flexibility for adaptation and application as a photometer or fluorometer, by only switching the photodetector position. The LED could also be easily switched, permitting application of the device for different purposes. The cost of the device, including the printing and electronic components, was lower than US$10. The use of 3D-printing enables the development of portable instruments for use in remote locations with a lack of research resources.