Unity: PC development, click the object with the mouse to trigger the object to change the material

Achieve the goal ： Click the object with the mouse to change the material of the object

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;
public class CMCSBottleClick : MonoBehaviour
{
    Material[] Mater = new Material[2];// texture of material 
    public GameObject tianpingShow;
    public GameObject PEOBottle;
    // Bind button 
    private void Awake()
    {
        PEOBottle.GetComponent<PEOBottleClick>().enabled = false;// Code component shutdown 
    }
    private void Start()
    {
        Mater[0] = Resources.Load<Material>("Material/meterial0");// Material replacement 
        Mater[1] = Resources.Load<Material>("Material/meterial27");
    }
    void OnMouseDown()
    {
        StartCoroutine("delayMedicalShow0");
       tianpingShow.GetComponent<MeshRenderer>().material = Mater[1];// Weighing display 
        this.GetComponent<Collider>().enabled = false;
    }
    IEnumerator delayMedicalShow0()
    {
        yield return new WaitForSeconds(1f);
        tianpingShow.GetComponent<MeshRenderer>().material = Mater[0];  // Material replacement 
        StartCoroutine("delayMedicalContainerAnimPlay0");
    }
    IEnumerator delayMedicalContainerAnimPlay0()
    {
        yield return new WaitForSeconds(2.5f);
        PEOBottle.GetComponent<PEOBottleClick>().enabled = true;
    }
}