diff --git a/esphome/components/mics_4514/sensor.py b/esphome/components/mics_4514/sensor.py
index 80c3524f66..59ccba235a 100644
--- a/esphome/components/mics_4514/sensor.py
+++ b/esphome/components/mics_4514/sensor.py
@@ -1,10 +1,14 @@
 import esphome.codegen as cg
+from esphome.components import i2c, sensor
 import esphome.config_validation as cv
-
-from esphome.components import sensor, i2c
-
 from esphome.const import (
+    CONF_AMMONIA,
+    CONF_CARBON_MONOXIDE,
+    CONF_ETHANOL,
+    CONF_HYDROGEN,
     CONF_ID,
+    CONF_METHANE,
+    CONF_NITROGEN_DIOXIDE,
     STATE_CLASS_MEASUREMENT,
     UNIT_PARTS_PER_MILLION,
 )
@@ -12,13 +16,6 @@ from esphome.const import (
 CODEOWNERS = ["@jesserockz"]
 DEPENDENCIES = ["i2c"]
 
-CONF_CARBON_MONOXIDE = "carbon_monoxide"
-CONF_NITROGEN_DIOXIDE = "nitrogen_dioxide"
-CONF_METHANE = "methane"
-CONF_ETHANOL = "ethanol"
-CONF_HYDROGEN = "hydrogen"
-CONF_AMMONIA = "ammonia"
-
 
 mics_4514_ns = cg.esphome_ns.namespace("mics_4514")
 MICS4514Component = mics_4514_ns.class_(
@@ -31,6 +28,7 @@ SENSORS = [
     CONF_ETHANOL,
     CONF_HYDROGEN,
     CONF_AMMONIA,
+    CONF_NITROGEN_DIOXIDE,
 ]
 
 common_sensor_schema = sensor.sensor_schema(
@@ -40,16 +38,7 @@ common_sensor_schema = sensor.sensor_schema(
 )
 
 CONFIG_SCHEMA = (
-    cv.Schema(
-        {
-            cv.GenerateID(): cv.declare_id(MICS4514Component),
-            cv.Optional(CONF_NITROGEN_DIOXIDE): sensor.sensor_schema(
-                unit_of_measurement=UNIT_PARTS_PER_MILLION,
-                state_class=STATE_CLASS_MEASUREMENT,
-                accuracy_decimals=2,
-            ),
-        }
-    )
+    cv.Schema({cv.GenerateID(): cv.declare_id(MICS4514Component)})
     .extend({cv.Optional(sensor_type): common_sensor_schema for sensor_type in SENSORS})
     .extend(i2c.i2c_device_schema(0x75))
     .extend(cv.polling_component_schema("60s"))
@@ -62,10 +51,6 @@ async def to_code(config):
     await i2c.register_i2c_device(var, config)
 
     for sensor_type in SENSORS:
-        if sensor_type in config:
-            sens = await sensor.new_sensor(config[sensor_type])
+        if sensor_config := config.get(sensor_type):
+            sens = await sensor.new_sensor(sensor_config)
             cg.add(getattr(var, f"set_{sensor_type}_sensor")(sens))
-
-    if CONF_NITROGEN_DIOXIDE in config:
-        sens = await sensor.new_sensor(config[CONF_NITROGEN_DIOXIDE])
-        cg.add(var.set_nitrogen_dioxide_sensor(sens))
diff --git a/esphome/const.py b/esphome/const.py
index 830f139077..bfb0167282 100644
--- a/esphome/const.py
+++ b/esphome/const.py
@@ -53,6 +53,7 @@ CONF_ALLOW_OTHER_USES = "allow_other_uses"
 CONF_ALPHA = "alpha"
 CONF_ALTITUDE = "altitude"
 CONF_AMBIENT_LIGHT = "ambient_light"
+CONF_AMMONIA = "ammonia"
 CONF_ANALOG = "analog"
 CONF_AND = "and"
 CONF_ANGLE = "angle"
@@ -110,6 +111,7 @@ CONF_CALIBRATE_LINEAR = "calibrate_linear"
 CONF_CALIBRATION = "calibration"
 CONF_CAPACITANCE = "capacitance"
 CONF_CAPACITY = "capacity"
+CONF_CARBON_MONOXIDE = "carbon_monoxide"
 CONF_CARRIER_DUTY_PERCENT = "carrier_duty_percent"
 CONF_CARRIER_FREQUENCY = "carrier_frequency"
 CONF_CERTIFICATE = "certificate"
@@ -263,6 +265,7 @@ CONF_ENUM_DATAPOINT = "enum_datapoint"
 CONF_EQUATION = "equation"
 CONF_ESP8266_DISABLE_SSL_SUPPORT = "esp8266_disable_ssl_support"
 CONF_ESPHOME = "esphome"
+CONF_ETHANOL = "ethanol"
 CONF_ETHERNET = "ethernet"
 CONF_EVENT = "event"
 CONF_EVENT_TYPE = "event_type"
@@ -361,6 +364,7 @@ CONF_HOURS = "hours"
 CONF_HSYNC_PIN = "hsync_pin"
 CONF_HUMIDITY = "humidity"
 CONF_HUMIDITY_SENSOR = "humidity_sensor"
+CONF_HYDROGEN = "hydrogen"
 CONF_HYSTERESIS = "hysteresis"
 CONF_I2C = "i2c"
 CONF_I2C_ID = "i2c_id"
@@ -477,6 +481,7 @@ CONF_MEDIA_PLAYER = "media_player"
 CONF_MEDIUM = "medium"
 CONF_MEMORY_BLOCKS = "memory_blocks"
 CONF_MESSAGE = "message"
+CONF_METHANE = "methane"
 CONF_METHOD = "method"
 CONF_MICROPHONE = "microphone"
 CONF_MIN_BRIGHTNESS = "min_brightness"
@@ -523,6 +528,7 @@ CONF_NBITS = "nbits"
 CONF_NEC = "nec"
 CONF_NETWORKS = "networks"
 CONF_NEW_PASSWORD = "new_password"
+CONF_NITROGEN_DIOXIDE = "nitrogen_dioxide"
 CONF_NOISE_LEVEL = "noise_level"
 CONF_NUM_ATTEMPTS = "num_attempts"
 CONF_NUM_CHANNELS = "num_channels"