Highly sensitive electrochemical determination of cariprazine using a novel Ti3C2@CoAl2O4 nanocomposite: application to pharmaceutical and biological sample analysis

Abstract

Cariprazine (CAR) is an atypical antipsychotic drug used for the treatment of schizophrenia and bipolar disorder. This study presents the development of a novel, highly sensitive electrochemical sensor based on a Ti₃C₂@CoAl₂O₂ nanocomposite-modified glassy carbon electrode (GCE) for the detection of CAR in pharmaceutical and biological samples. The innovative Ti₃C₂@CoAl₂O₂ composite, synthesized and characterized through Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy coupled with energy-dispersive spectroscopy, and thermogravimetric analysis, revealed exceptional structural integrity, morphology, composition, and thermal stability. The electrochemical properties of the modified electrode were evaluated using cyclic voltammetry and electrochemical impedance spectroscopy, demonstrating enhanced conductivity, an increased electroactive surface area, and reduced charge transfer resistance compared to the bare GCE. Differential pulse voltammetry was employed for CAR detection under optimized conditions, yielding a linear range of 0.2-5.6 μM with a regression equation I_pa (μA) = 0.133 C_CAR (μM) + 0.09 (R² = 0.993). The limit of detection and limit of quantification were determined as 0.02 µM and 0.07 µM, respectively, highlighting the sensor's high sensitivity. The modified electrode exhibited excellent repeatability with a relative standard deviation (RSD) of = 2.9% and reproducibility (RSD = 2.8%), along with strong selectivity against common interfering substances. The sensor was successfully applied to human blood serum, urine, and CAR tablets, achieving high recovery values (98.52-103.94%), confirming its reliability for real-sample analysis. These findings underline the novelty and potential of the Ti₃C₂@CoAl₂O₂-modified GCE as a powerful tool for the accurate, selective, and sensitive determination of CAR in clinical and pharmaceutical applications.

Keywords: Cariprazine; Differential pulse voltammetry; Electrochemistry; Modified electrode; Nanocomposite; Rare disease.

Fig. 1

FTIR spectra of prepared CoAl₂O₄, Ti₃C₂ MXene, and Ti₃C₂@CoAl₂O₄ nanocomposite

Fig. 2

XRD patterns of synthesized CoAl₂O₄, Ti₃C₂ MXene, and Ti₃C₂@ CoAl₂O₄ nanocomposite

Fig. 3

SEM images of as-prepared CoAl₂O₄ (a–c) [37], as-prepared Ti₃C₂ MXene (d–f), and Ti₃C₂@CoAl₂O₄ nanocomposite (g–i)

Fig. 4

SEM–EDS analysis and the elemental composition of (a) CoAl₂O₄, (b) Ti₃C₂ MXene, and (c) Ti₃C₂@CoAl₂O₄ nanocomposite

Fig. 5

TGA of as-prepared CoAl₂O₄, Ti₃C₂ MXene, and Ti₃C₂@CoAl₂O₄ nanocomposite

Fig. 6

(A) CV and (B) EIS spectra of the unmodified GCE (a), CoAl₂O₄/GCE (b), Ti₃C₂/GCE (c), and Ti₃C₂@CoAl₂O₄/GCE (d); the inset is the equivalent circuit for the EIS test of Ti₃C₂@CoAl₂O₄/GCE (Rs, electrolyte solution resistance; Rct, element of interfacial electron transfer resistance; CPE, constant phase element; W, Warburg impedance resulting from the diffusion of ions)

Fig. 7

(A) DPV voltammograms of 0.07 mM CAR at various pH (3.0–8.0) of BR on the Ti₃C₂@CoAl₂O₄/GCE and (B) the impact of pH on the peak potential (E_pa) of CAR

Fig. 8

(A) Scan rate effect of 0.07 mM CAR, (B) plot of I_pa (μA) vs. v^1/2 (mV s⁻¹)^1/2, (C) plot of log I_pa (μA) vs. log v (mV s⁻¹), and (D) plot of E_pa vs. ln v

Scheme 1

The plausible electrooxidation process of CAR

Fig. 9

(A) DPVs of Ti₃C₂@CoAl₂O₄/GCE in BR (0.1 mol L⁻¹, pH = 4.0) containing various concentrations of CAR